Test Two Bio 1000 – Flashcards
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Why are quick disconnect fittings used?
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To provide a quick means to connect or disconnect a fluid line without loss f fluid or entrance of air into the system.
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What are the two basic parts of a virus?
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nucleic acid and protein coat
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What is different about the nucleic acids in a virus?
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some viruses have DNA, some have RNA
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Define lytic cycle
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destroys cell by breaking many viruses at a time
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DNA is the control molecule, what two things does it control?
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everyday functions of the cell and what gets passed to the next generation
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What does DNA stand for?
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deoxyribonucleic acid
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What does RNA stand for?
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ribonucleic acid
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Both DNA and RNA are polymers of what?
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nucleotides
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What is the macromolecule of nucleotides?
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nucleic acid
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What is another name for nucleic acid?
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polynucleotide
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What is the difference between DNA and RNA?
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DNA is double-stranded, RNA is single-stranded
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What distinct sugar does DNA have?
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deoxyribose - missing O2
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What distinct sugar does RNA have?
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ribose
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What bases do DNA and RNA have in common?
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adenine, cytosine, and guanine
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What is the structure of a nucleotide? 3
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five-carbon sugar, phosphate group, nitrogenous base
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What two groups do the nitrogenous bases for DNA fall into?
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pyrimidines and purine
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What bases are in pyrimidine?
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cytosine, uracil, and thymine
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What bases are in purine?
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adenine, guanine
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What is specific about the structure of a purine?
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it is double rings
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Define origins of replication
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specific sites on the DNA where replication will start
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Define replication "bubble"
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small section of opened DNA
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Define parental strands
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original DNA strands
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Define daughter strands
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new strands being formed - semi conservative model
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Define DNA polymerase
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enzyme that links individual nucleotides into polymers - comes in to make short strands
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What does DNA polymerase make?
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a DNA polymer
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Define DNA ligase
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enzyme that joins short DNA strands together
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What is the direction daughter strands can only be built?
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five prime (5') to three prime (3')
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Where must nucleotides attach in DNA replication?
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to the three prime end of the strand
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DNA contains the info needed to build what?
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protein molecules
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What has to happen to DNA when it is needed outside the cell?
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have to make a copy of the DNA and it can then leave
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What are the two steps for protein products to be made?
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transcription and translation
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Define transcription
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copying the info on the DNA into a form that is able to leave the nucleus... the RNA
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Define translation
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using that info to make the product
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What is a triplet/codon?
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a group of three nitrogenous bases
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What does each codon have?
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a code for amino acids
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What are amino acids?
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monomers of proteins
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What are the three types of RNA?
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messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA)
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What is messenger RNA?
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created in the nucleus, brings message to ribosome - made when you transcribe DNA
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What is transfer RNA?
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found in cytoplasm, transfers amino acids to the ribosome - carries amino acid to mRNA
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What is ribosomal RNA?
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found at ribosome, important in facilitating protein synthesis - site for protein synthesis
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What is special about ribosomes?
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they are not membrane-bound organelles
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What is a promoter?
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a section of DNA that marks where transcription begins for each gene
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What is a promoter a specific binding site for?
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RNA polymerase
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What is the function of a promoter?
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determines which strand gets copied
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What does RNA polymerase do?
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links RNA nucleotides and makes an RNA polymer
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What are the parts of mRNA that must be modified before leaving the nucleus?
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guanine cap, poly-a tail, introns removed, exons spliced together
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Explain introns
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they are removed, stay in the nucleus
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Explain exons
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are spliced together and exit nucleus and make the mRNA
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What are the two subunits ribosomes are made of?
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protein and rRNA
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What is an initiation codon?
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elongation of polypeptide
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Explain what happens at an initiation codon?
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mRNA binds to smaller subunit of ribosome at a binding site - initiator tRNA binds to the start codon - large ribosomal subunit binds to small unit, with the initiator tRNA fitting into the 'P' site
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Where does the initiator tRNA go?
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in the 'P' site
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Where does the second tRNA go?
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in the 'A" site
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What kind of bond joins the amino acids carried by the tRNA?
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peptide bond
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Explain what happens at the 'P' and 'A' site?
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the initiator tRNA leaves the 'P' site - the second tRNA moves into the 'P' site, carrying the dipeptide - the next tRNA enters the 'A' site, and the sequence repeats - the mRNA moves down to facilitate the reading of the next codon
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Define silent mutation
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causes no change in amino acid
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Define missense mutation
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changes from one amino acid to another
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Define nonsense mutation
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changes an amino acid codon to a stop codon - makes them shorter
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Define frameshift mutation
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changes all subsequent codons
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What are the three methods of mutations?
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deletion, insertion, and substitution
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What are the other 3 parts a virus may or may not have?
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a membranous envelope, enzymes, glycoprotein spikes
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Why might a virus need to bring enzymes?
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if they're not present in target cell, it needs to bring them
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What are glycoprotein spikes?
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protein modified by a sugar - the spikes help attach
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List the three ways how a new virus can appear
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`mutation of existing virus, crossing species, spread from isolated populations
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What does AIDS stand for?
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auto immunodeficiency syndrome
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What is AIDS caused by?
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HIV - human immunodeficiency virus
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What is a retrovirus?
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brings it's own enzymes - reverse transcriptase
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What is reverse transcriptase?
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reverses transcription - RNA->DNA
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Bacteria doe not use sexual reproduction, what are the three methods of sharing DNA?
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transformation, transduction, conjugation
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Define transformation
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getting a fragment of DNA from another bacterial cell
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Define transduction
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fragment of DNA from another bacteria cell (former phage host)
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Define conjugation
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sex pili - union between two bacterial cells
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What is the fundamental unit of life?
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the cell
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Was inductive or deductive reasoning used to come up with the Cell Theory?
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inductive - derives general principles from a large number of specific observations
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When was the Cell Theory developed?
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200 years after microscope invention
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What does the Cell Theory state? (2)
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all living things are made of cells and all cells come from other cells
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How is a light microscope used?
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light is passed through a specimen, and through glass lenses which bend the light to magnify the image
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What does an electron microscope use to see the image?
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electron stream instead of light
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What is the difference between a light and electron microscope?
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electron has a much higher resolution
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What does a light microscope magnify up to? electron?
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1,000; 100,000
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What are the two kinds of electron microscopes?
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scanning and transmission
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Explain the scanning electron microscope
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clear view of surface of cell/organelle
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Explain the transmission electron microscope
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gives very clear view of inside of cell/organelle
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What is the difference between magnification and resolution?
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magnification-how bigresolution-how clear
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Why is cell size critical? (2)
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must have enough space to hold all necessary components and must be small enough to acquire nutrition and dispose of wastes
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Define surface to volume ratio
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more surface area is better for volume - controls how big the cell gets
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What does the plasma membrane do for the cell?
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forms a flexible boundary between the living cell and its surrounding
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What is the phospholipid bilayer?
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phospholipids form a two-layer sheet - hydrophilic heads and hydrophobic tails
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What other structures are embedded or attached to the bilayer?
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proteins (channel) and cholesterol (animals)
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What is cellular metabolism?
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how your cell is working
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Explain the nucleus
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function-hold and protect DNAstructure-nuclear envelope or double-membrane with pores
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Explain the smooth ER
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function-synthesize lipids, store calcium ions, process drugsstructure-membrane tubules
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Explain the rough ER
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function-make more membrane, modify proteinsstructure-folded membrane with bound ribosomes
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Explain the Golgi apparatus
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function-modifies proteinsstructure-flattened sacs of membrane that are not connected
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Explain lysosomes
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function-digestion of food, destruction of bacteria, recycle damaged organellesstructure-contains hydrolytic enzymes in a membranous sac
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Explain vesicle
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function-structure-
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Explain vacuole
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function-food vacuole, ventral vacuole in plants, contractile vacuolestructure-large membranous sacs
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Explain chloroplasts
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function-photosynthesisstructure-double membrane with stroma
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Explain mitochondria
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function-cellular respiration, converts chemical energy of food to ATPstructure-organelle with double membrane with cristae/matrix
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The nucleus contains most(?) of the DNA, ____, in structures called _____
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both the mitochondria and chloroplasts have DNA; in association with proteins; chromosomes
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Each macromolecule is one what?
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one chromosome - one strand of DNA
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What is chromatin?
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a relaxed structure - long thin fibers that DNA is in for most of the cell's life
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What is the nucleolus the site of?
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rRNA synthesis - found in ribosomes
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How can ribosomes be in prokaryotic cells if they are organelles?
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they're non membrane bound
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What are ribosomes needed for?
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protein synthesis
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How can ribosomes be seen in a cell?
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free or bound
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What are the 8 organelles included in the endomembrane system?
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nuclear envelope, smooth and rough ER, Golgi apparatus, lysosome, transport vesicles, vacuoles, plasma membrane
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What organelles are connected physically in the endomembrane system? (3)
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nuclear envelope, smooth and rough ER
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What organelles are connected functionally in the endomembrane system? (5)
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golgi apparatus, lysosome, transport vesicles, vacuoles, plasma membrane
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What is the smooth ER?
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network of interconnecting membrane tubules
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What assists the functions of the smooth ER?
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enzymes embedded in the membrane
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What is the rough ER?
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folded membrane which is studded with bound ribosomes
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What is the phrase for the Golgi apparatus?
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"warehouse, finishing, and shipping factory" of the cell
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Where are lysosomes found and what does it mean?
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only in animal cells and means "breakdown body" - recycling center
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What process will the enzymes in lysosomes be facilitating?
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hydrolysis
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What are 2 disorders caused by lysosomes?
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Pompe's disease and Tay-Sachs disease
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What is Pompe's disease?
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missing enzyme that breaks down glycogen
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What is glycogen?
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animal carb for storage in muscles and liver
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What is Tay-Sachs disease?
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missing enzyme to break down a specific lipid
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What specific lipid is unable to be broken down with Tay-Sachs disease?
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lipid stored in the nervous system (brain)
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Define contractile vacuoles
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has spokes that bring the water in single-celled organelles, lives in water, help cell control water coming in and out
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What organelles are not part of the endomembrane system? (5)
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mitochondria, chloroplast, cytoskeleton, cilia and flagella
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Where are mitochondria found?
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in nearly all eukaryotic cells
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What is matrix? (mitochondria)
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thick liquid inside the membrane
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What is cristae? (mitochondria)
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the folds of the membrane
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Where are chloroplasts found?
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only in photosynthetic eukaryotes
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What does the Endosymbiotic Theory state?
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mitochondria and choloroplasts evolved from prokaryotic cells
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How are mitochondria and chloroplasts similar?
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have their own DNA, ribosomes, and method of reproduction
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What is the cytoskeleton?
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protein fibers that extend throughout cytoplasm
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What is the function of the cytoskeleton?
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structural support, assist in some types of cell movement, and help regulate cellular activities
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What are the three types of fibers that the cytoskeleton is composed of?
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microfilaments, intermediate filaments, and microtubules
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Define microfilaments
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solid rods of globular actin proteins that support cell shape and movement
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Define intermediate filaments
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fibrous coiled proteins that reinforce cell shape and anchor organelles
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Define microtubules
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hollow tubes of globular tubular proteins and help with shape and support cell and act as "tracks" or "roadways" for movement within the cell
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What are cilia?
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short numerous cellular appendages
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What are flagella?
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longer and usually fewer cellular appendages
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What are cilia and flagella used for?
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locomotion
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What is the extracellular matrix?
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holds cells in an animal tissue together, protects and supports plasma membranes, and contains materials that transmit signals - bind to embedded proteins
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What are the three types of junctions in animal cells?
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tight, anchoring, gap
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Define tight junctions and give an example
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bind cells tightly in leakproof sheet - veins and stomach
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Define anchoring junctions and give an example
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rivet cells with cytoskeletal fibers, forming strong sheets - muscles
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Define gap junctions and give an example
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channels for communication between cells - in the heart
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What is the type of junction in plant cells?
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plasmodesmata
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Define plasmodesmata
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communication channels between plant cells
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Why do plant cells need to communicate?
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to protect itself
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Define diffusion
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molecules moving from an area of high concentration to low concentration
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Define concentration gradient
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change in concentration of particles/solute for one are to the next
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Define passive transport
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movement of substances down a concentration gradient not requiring energy
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Define osmosis
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the diffusion of water
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How does water move across a membrane?
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by passive transport
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Define tonicity and what is it based on
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tendency of a cell to gain or lose water - based on the number of particles/solute
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Define osmoregulation
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control of water balance
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Define plasmolysis
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plant cell membrane pulling away from cell wall when in a hypertonic solution
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Define facilitated diffusion
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transport proteins in membranes assisting molecules to move down a concentration gradient
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Does facilitated diffusion require energy and why?
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yes because it is going along with the gradient
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Define active transport
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moves molecules across a membrane against the concentration gradient
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Does active transport require energy and why?
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yes because you are going against the gradient
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Define endocytosis
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method of bringing bulky items into a cell
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Define exocytosis
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method of removing bulky items from a cell
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Define energy
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the capacity to cause change or perform work
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Explain what work is
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work is performed when an object is moved against an opposing force( gravity) and is the capacity to rearrange matter (chemical compounds)
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What are the two kinds of energy?
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kinetic and potential
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Define kinetic energy
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the energy of motion
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What are two types of kinetic energy?
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heat and light
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Explain how heat is kinetic energy
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thermal energy, or form of kinetic energy associated with the random movement of molecules or atoms in a body of matter
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Why is heat not usable by living organisms?
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can't capture and use for cellular work because it is too random
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Explain how light is kinetic energy
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form of kinetic energy that can be harnessed to perform work.. as in photosynthesis
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Define potential energy
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stored energy that an object has as a result of its location or structure
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What is an example of potential energy?
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chemical energy
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Explain chemical energy
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the potential energy of molecules - the most important type of energy for living organisms
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Define thermodynamics
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the study of energy transformation that occur in a collection of matter
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Define the term system
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refers to the matter under study at any given time
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Define the term surroundings
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everything outside the system under study
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What is another name for the first law of thermodynamics and what is it?
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also called the law of energy conservation - energy can be transferred and transformed, but it cannot be created or destroyed
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What does the second law of thermodynamics state?
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energy conversions reduce the other of the universe and increase its entropy
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What is entropy mean?
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disorder
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What are the two types of chemical reactions?
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endergonic and exergonic
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What is an endergonic reaction?
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chemical reaction requiring an input of energy
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What does an endergonic reaction produce?
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a product molecule rich in potential energy
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What is an example of an endergonic reaction?
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photosynthesis
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Explain photosynthesis
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takes energy-poor reactants of carbon dioxide and water and produces energy-rich sugar molecules
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What is an exergonic reaction?
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chemical reaction which releases energy
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What does an exergonic reaction produce?
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product molecule(s) with less potential energy than the original reactants
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What is an example of an exergonic reaction?
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cellular respiration
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Explain cellular respiration
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uses oxygen and energy-rich sugar molecules and produces chemical energy in immediately usable form
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What does ATP stand for?
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adenosine triphosphate
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What is the purpose of ATP?
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powers almost all cellular work
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Hydrolysis of ATP is exergonic or endergonic? Explain
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exergonic because it is breaking down by adding water
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What would be the reverse of the hydrolysis of ATP?
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phosphorylation
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Define phosphorylation
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adding a phosphate group to a molecule
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What are the three main types of cellular work?
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chemical, mechanical, and transport
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Define chemical cellular work
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a lot of chemical processes need energy to start
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Define mechanical cellular work
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keeping it on track
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Define transport cellular work
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active transport against the gradient/force
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What is activation energy?
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the amount of energy that reactants must absorb to become activated and start a chemical reaction
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How is activation energy a "barrier" to a reaction?
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it lowers the energy by facillitating
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What type of macromolecule are enzymes?
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protein
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What does an enzyme do?
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increase the rate of a reaction, without undergoing any molecular change themselves
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How are enzymes able to perform their function? (3)
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they do not add energy to the reaction, lower the activation energy, and can be used over and over
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What is denaturing?
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loss of shape - breaking down
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What are the three causes of denaturation?
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temperature, pH, concentration of salt
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Define cofactors
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non-protein "helper" for an enzyme
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What are the two properties of cofactors
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some enzymes will not function without them and may be organic or inorganic
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What is a coenzyme
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an organic cofactor
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What are types of inorganic cofactors?
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ions of zinc, iron, copper
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What is a type of organic cofactor?
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vitamins
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What is an inhibitor?
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any chemical that interferes with an enzyme's activity
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What are the two types of inhibitors?
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competitive and noncompetitive
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Define competitive inhibitors
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fits at least partially in active site to physically block it
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Define noncompetitive inhibitors
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allosteric site - attaches on enzyme and changes the shape of active site
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What is a type of pesticide?
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malathion - blocks acetylcholinesterase which is needed for nerve transmissions
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What are two types of poisons and define?
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cyanide - inhibits ATP formationsarin - blocks acetylcholinesterase
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What is a type of drug?
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ibuprofen/aspirin - blocks enzyme that allows you to feel pain, as well as working as an anti-inflammatory
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What is a type of antibiotic?
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penicillin - blocks enzyme that facilitates cell wall formations
