Principles of Biology 1 chapters 1-3 – Flashcards
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Define Biology
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The study of life. Webster defines it as the science of life or living matter in all its forms and phenomena, especially with reference to origin, growth, reproduction, structure, and behavior.
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Define Homeostasis
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Keeping iternal conditions sonsistant despite external change(i.e. body temperature)
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Define Domains
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Living organisms which are classified into three major groups (bacteria, archaea, eukarya)
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What are the characteristics of a prokaryotic cell?
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Contains no nucleua; has DNA, but is not contained in a nucleus.
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What are the characteristics of a eukaryotic cell?
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has a nucleus which contains/house genetic material.
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How is food obtained?
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Ingested, made, or absorbed
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Define flora bacteria
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bacteria that helps fight infection
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What is the main differnce between archaea and bacteria?
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while both are unicellular, prokaryotic, and absorb food, ARCHAEA HAVE UNIQUE CELL STRUCTURES AND IS NOT KNOWN TO CAUSE INFECTION.
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Define extremophiles
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the abiltiy to live in some very odd places.
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What are the simularities between living organisms?
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cells, genetic material, simular molecules, and chemical reactions
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List the basic levels of organization of living things from the most specific to most general.
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Atoms -> Molecules -> Organelles (i.e. neuculus) -> Cells -> Tissues -> Organs -> Organism -> Population -> Community -> Ecosystem
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Define Population
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all members of the SAME species in a given environment/area
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Define Community
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all members of ALL species in a given area.
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Define ecosystem
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community and interaction with non living organisms such as; water, pollution, and weather.
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Define scientific method
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A process of examination and discovery of natural phenomena involving making observations, constructing hypotheses, testing predictions, experimenting, and drawing conclusions and revising them as necessary.
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Does the experimental group or the control group recieve the placibo?
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control group
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Define adaptation
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the process by whice, as a result of natural selection, organisms become better matched to their environment; also a specific feature such as quills or webbed feet.
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Define evolution
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a change in allele frequencies of a population. :allele- One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
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Define inheritance
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the transmission of traits from parents to offspring via genetic information; also known as heritability
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Why does a cell need to take in nutrients and expel waste quickly?
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because they are so small.
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Define large surface area to volume ratio
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a cell that needs a large surface area relative to a small volume.
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How is the prokaryotic cell different from the eukaryotic cell?
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Relatively smaller, a single loop of dna, not in nucleus, oxygen is NOT always needed, and does not have the precsence of membrane-bound organeles.
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How is the eukaryotic cell different from a prokaryotic cell?
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Relatively larger, several linear pieces of DNA (chromosomes), housed in the necleus, oxygen IS usually needed, and there is the presence of membrane-bound organeeles.
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Define organelle
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a compartment in the cell, separated by a membrane, where a specific, specialized function takes place.
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What four characteristics are in a cell?
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Ribosomes, cell membrane, cytoplasma, and loop of DNA.
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List the prokaryotic cell structures
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Cell membrane, Nucleoid, Ribosomes, Cytoplasm, Cell wall, Flagella, Capsule, Pili, Plasmid, Spores
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What is the function of the cell membrane?
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it is the outter boundary of the cell in a prokaryotic and an eukaryotic cell.
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What is the function of the nucleoid?
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it is the area where a single loop of DNA is located (DNA is the blueprints) Only found in the prokaryoic cell.
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What is the function of the ribosomes?
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they produce proteins in a prokaryotic and an eukaryotic cell.
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What is the function of the cytoplasm?
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the liquid portion of a cell in a prokaryotic and an eukaryotic cell.
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What is the funtion of a cell wall?
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an extra layer on the surface of the cell used for shape and protection. Both prokaryotic and an eukaryotic cells have a cell wall but they are different.
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What is the funtion of a flagella?
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it is the tail that helps with movement found in a prokaryotic and an eukaryotic cell.
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What is the funtion of a pili?
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microscopic hairs on the bacteria surface which is found only in a prokaryotic cell.
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What is the funtion of a plasmid?
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An extra loop of DNA which can contain resistance genes. Bacteria that contains these genes become antibiotic resistant. Found only in prokaryotic cells.
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What is the funtion of spores?
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bacteria cells can convert themselves to spores as a survival strategy (i.e. antrhrax and tetanus) Found only in prokayotic cells.
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What does a basic prokaryote consist of?
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plasma membrane, cytoplasm, DNA, cell wall, pili, flagellum
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What are the key features of a plant cell?
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rectangular in shape. Presence of cell wall. Presence of chloroplasts. Presence of a central vacuole.
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What are the key features of an animal cell?
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roundish in shape. No cell wall, no chloroplasts, and no central vacuole.
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What is the funtion of a plant cell wall?
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A rigid layer on the surface of the cell membrane made up of cellulose (a.k.a. fiber).
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If you isolated a cell that contained a cell membrane, ribosomes, cytoplam and genetic material what could you conclude?
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that it is a cell. All cells contain those characteristics.
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What is the function of a cytoskeleton?
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A series of fibers that runs through the cell for support.
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What is the function of cilia?
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responsible for "Smoker's Cough". Microscopic "hairs" on the cell surface to filter bebris. When you smoke you loose ability to filter.
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What is the function of a nucleus?
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Houses the chromosomes.
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What does SER stand for?
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Smooth Endoplasmic Reticulum (SER)
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What is the role of SER in the liver?
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to detoxify enzymes (alcohol, medicine) is created upon exposure to toxins.
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How does SER relate to tolerence?
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each exposure to a toxin resleases more and more SER.
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What does RER stand for?
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Rough Endoplasmic Reticulum
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Describe Glycoprotein Synthesis
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The surface of the RER is studded with ribosomes with create proteins. These proteins then enter the RER where that are modified. This involves adding a sugar which serves to label (tell where to go) to identify that protein. THE ADDRESS ON A CARD.
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What is the function of the golgi complex?
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sorts contents from the ER and routes them to their appropriate locations. THE POST OFFICE
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What is the function of lysosomes?
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contains digestive enzymes that break down items. THE CLEANING CREW
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What is Tay-Sacha disease?
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has no lysosomes. Fatal. lipids accumulate and eventually burst (cell death). people die from this between 4-5 years of age.
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What is the function of the central vacuole?
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Only in plants. Stores the water and nutrients.
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What is the function of chloroplasts?
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Only in plants. Photosynthesis. Plants convert carbon dioxide into glucose and oxygen.
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What is the function of Mitochondria?
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Aerobic cellular respiration. Breaks down glucose to make ATP for the cells. This is increased by exercise.
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What is the theory of endosymbiosis?
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at some point certain bacteria are engulfed by a larger cell. Bacterian can be inside a larger cell in a symbiotic relationship.
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Define element
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a group of the same type of (particle of matter that cannot be divided farther) atom .
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How many natural elements does a living thing require?
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25
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How many natural elements are there?
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92
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What are the four major elements needed by living things?
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Carbon, Hydrogen, Oxygen, Nitrogen (all of which are the smallest particles in the human body)
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Define trace elements with examples
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elements needed by living things but in much smaller amounts. Examples are; cacium, sodium, iron, potasium, magnesium
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What are the three main subatomic particles?
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protons, neutrons, and electrons
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What happens if an atoms has more protons than electrons?
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the atom will have a negative charge.
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What particle weighs the most at 1 unit?
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protons
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How much does a neutron weigh?
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1 unit
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what subatomic particle does not have a weight?
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electrons
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What charge does a proton have?
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positive (+)
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What charge does an electron have?
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negative (-)
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The atomic core (nucleus) is composed of which two particles?
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protons and neutrons. The atom core will have a positive charge due to the protons.
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Why do electrons stay with atom cores?
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Electrons have a negative charge while an atom core is positivly charged by the protons and opposites attract.
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In a basic atom that has 2 protons, 2 neutrons, and 2 electrons what is the charge of the atom?
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Neutral. (number of protons= number of electrons)
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Define ion
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An atom that has an electrical charge due to an uneven number of protons and electrons.
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What is the difference between Na and Na?
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Na is neutral while Na? has more protons than electrons which makes the ion negative.
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Define atomic number
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the number of protons an atom has. It determines the atom's identity. Found in the lower left beside an atomic symbol. (subscript)
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Define atomic weight
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the number of protons plus neutrons. Found in the upper left beside the atomic symbol. (superscript)
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Define Isotope
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members of the same element with different weights.
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What makes an isotope radioactive?
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when an isotope is not stable and begins to eject subatomic particles until it becomes stable.
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Does a radioactive isotope stay that way forever?
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no, eventually it ejects enough particles to become stable. (i.e. soil)
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What is an example of a radioactive ejects protons?
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it becomes another element
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What is an example of a radioactive ejects neutrons?
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it becomes another isotope
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What is an example of a radioactive ejects electrons?
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the charge of the element will change.
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Define half-life
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the amount of time it takes for half of a given amount of a radioactive isotope to staabilize.
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Why is exposure to radioactivity dangerous?
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as the subatomic particles are ejected, they cross cell membranes and damage the cellular molecules.
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Define free radical
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charged particles that do damage to other molecules in the cell (such as DNA) The cells that move the fastest are damaged the most. Cells cannot reproduce so they die.
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Define irradiation
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purposefully exposing something to radiation in an attempt to kill certain cells with radiation.
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Describe radiation therapy
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Uncontrolled cancer cells divide very fast. Radiation causes free radical damage that kills cells that divide fast.
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Define food irradiation
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the exposure of food to radiation in an attempt to kill microbes living on it. It also kills spores.
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What is the most important subatomic particle in determining how and if two atoms can bond/interact with eachother?
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electrons
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How many electrons can fit on outter shells of an electron shell diagram?
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8
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What happens if the outter shell of an electron shell diagram is full?
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it will not bond with other atoms
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Will a Carbon atom with six electrons bond?
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Yes, outter shell is less than 8
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Why do atoms form chemical bonds?
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the goal of the bond is for all atoms involved in te bond to attempt to fill their outer electrom shell.
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Define ionic bond
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a bond created by the transfer of one or more electrons from one atom to another; the resulting atoms, now called ions, are charged oppositely and so attract each other to form a compound. The bond is strong but weak in water.
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How do ions form?
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one atom is almost full in the outer electron shell and the other is almost empty. The almost empty one gives its elecrons to the almost full one.
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Define covalent bond
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the sharing of electrons, not donated.
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What are the general properties of a convalent bond?
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strong bonds which do not deminish in water.
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What happens when there is a convalent bond?
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this happens when two or more atoms are near each other and they all NEED electrons. If this happens, no atoms will donate electrons.
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Define polar covalent bond
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when two atoms share electrons equally.
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Define non-polar covalent bond
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when two atoms share electrons unequally.
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Which atoms gain the electron closer in a polar convalent bond?
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the atomic symbol that has the most protons.
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Define hydrogen bond
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a type of weak chemical bond formed between the slightly positively charged hydrogen atoms of one molecule and the slightly negatively charged atoms of another. Holds DNA.
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What are the general properties of a hydrogen bond?
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weak, break and re-form often
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When can a hydrogen bond form?
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it can only happen if a polar covalent bond has already occurred. This is the unequally sharing of electrons that puts weak + and - charges on certain atoms.
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If two polar molecules are near eachother; what will they do?
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cling together
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What two ions contribute to pH of a solution?
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H+ (hydrogen) and OH- (hydroxide ion)
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Define acids
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something added to water that donates H+ ions to the colution (so there are more H+ than OH-)
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Define base
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something added to water that removes H+ ions from a solution (so by default, there are more OH- ions)
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What value range does acids have?
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0-6.9
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What value range does neutral bases have?
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7.0
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What value range does the basic pH scale have?
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7.1-14
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What chemicals prevent pH changes?
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molecules called "buffers"
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What is the pH level of a human?
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7.4
