Test Two Bio 1000

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

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