bio exam 1

biosphere

the entire portion of Earth inhabited by life; the sum of all the planet's ecosystems

community

an assemblage of all the populations of organisms living close enough together for potential interactions

domain

a taxonomic category above the kingdom level. the three domains of life are Archaea, bacteria, and Eukarya

ecosystem

all the organisms in a given area, along with the nonliving (abiotic) factors with which they interact; a biological community and its physical environment

emergent properties

new properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases

gene

a discrete unit of hereditary info consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). most of the genes of a eukaryote are located in its chromosomal DNA; a few are carried by the DNA of mitochondria and chloroplasts

gene expression

the process whereby genetic info flows from genes to proteins; the flow of genetic info from the genotype to the phenotype

hypothesis

a testable explanation for a set of observations based on the available data

molecule

two or more atoms held together by covalent bonds

organ

a specialized structure composed of several different types of tissues that together perform specific functions

organelle

a membrane-enclosed structure with a specialized function within a cell

organism

an individual living thin, consisting of one or more cells

population - a group of individuals belonging to one species that live in the same geographic area and can potentially interbreed

systems biology

an approach to studying biology that aims to model the dynamic behavior of whole biological systems based on a study of the interactions among the system's parts

technology

the application of scientific knowledge for a specific purpose, often involving industry or commerce but also including uses in basic research

theory

a widely accepted explanatory idea that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence

tissue

an integrated group of cells with a common function, structure, or both

acid

a substance that increases the hydrogen ion (H+) concentration in a solution

aqueous solution

a solution in which water is the solvent

atomic mass

the total mass of an atom; also called atomic weight. given as a whole number, the atomic mass approximately equals the mass number

atomic number

number of protons in each atom of a particular element

base

a substance that decreases the hydrogen ion (H+) concentration in a solution

buffer

a chemical substance that minimizes changes in pH by accepting hydrogen ions from or donating hydrogen ions to solutions

chemical bond

an attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. the bonded atoms gain complete outer electron shells

chemical reaction

the making and breaking of chemical bonds, leading to charges in the composition of matter

covalent bond

a type of strong chemical bond in which two atoms

electronegativity

the attraction of a given atom for the electrons of a covalent bond

evaporative cooling

the process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest energy changing from the liquid to the gaseous state

heat

thermal energy in transfer from one body of matter to another

hydrogen bond

weak; formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule

ionic bond

chem. bond resulting from the attraction between oppositely charged ions

mass number

sum of protons and neutrons

nonpolar covalent bond

a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

pH scale

measure of the acidity of a solution, ranging from 0 - 14; potential hydrogen/concentration of hydrogen ions

polar covalent bond

covalent bond between atoms that differ in electronegativity

salt

a compound resulting from the formation of an ionic bond

solute

a substance that is dissolved in a solution

solvent

the dissolving agent of a solution

surface tension

measure of how difficult it is to stretch or break the surface of a liquid

temperature

measure in degrees of the average thermal energy of the atoms and molecules in a body of matter

thermal energy

kinetic energy due to the random motion of atoms and molecules; energy in its most random form

trace element

an element that is essential for life but required in extremely minute amounts

amino acid

an organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins

amino group

a chemical group consisting of a nitrogen atom bonded to two hydrogen atoms

anabolic steroid

a synthetic variant of the male hormone testosterone that mimics some of its effects

carbohydrate

member of the class of biological molecules consisting of single-monomer sugars (monosaccharides), two-monomer sugars (disaccharides), and polymers (polysaccharides)

carbonyl group

a chemical group consisting of carbon atom linked by a double bond to an oxygen atom

carboxyl group

a chemical group consisting of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group

cellulose

structural polysaccharide of plant cell walls composed of glucose monomers; linked by hydrogen bonds into cable-like fibrils

chitin

structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods

cholesterol

a steroid that is an important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids, such as hormones

dehydration synthesis

builds molecules by taking away water

denaturation

process which protein unravels; can be caused by changes in pH, salt concentration, or high temps.

disaccharide

a sugar molecule consisting of two monosaccharides linked by a dehydration reaction

enzyme

macromolecule, usually a protein, that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction

fat

a lipid composed of three fatty acids linked to one glycerol molecule; a triglyceride; most function as energy-storage molecules

functional group

a specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions

glucose

a six-carbon monosaccharide that serves as a building block for many polysaccharides and whose oxidation in cellular respiration is a major source of ATP for cells

glycogen

an extensively branched glucose storage polysaccharide found in liver and muscle cells; animal equivalent of starch

hydrocarbon

an organic compound composed only of the elements carbon and hydrogen

hydrolysis

a chemical reaction that breaks bonds between two molecules by the addition of water; process by which polymers are broken down and an essential part of digestion

hydroxyl group

a chemical group consisting of an oxygen atom bonded to a hydrogen atom

isomers

organic compounds with the same molecular formula but different structures

lipid

an organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic; include fats, phospholipids, and steroids; insoluble in water

macromolecule

giant molecule (polysaccharide, protein, or nucleic acid) formed by the joining of smaller molecules, usually by a dehydration reaction

methyl group

a chemical group consisting of a carbon atom bonded to three hydrogen atoms

monomers

the subunit that serves as a building block of a polymer

monosaccharide

simplest carbohydrate; a simple sugar with a molecular formula that is generally multiple of CH2O

nucleic acid

a polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular structures and activities; DNA and RNA

organic compound

a chemical compound containing the element carbon and usually the element hydrogen

peptide bond

covalent bond between two amino acid units in a polypeptide, formed by a dehydration reaction

phosphate group

a chemical group consisting of a phosphorous atom bonded to four oxygen atoms

phospholipid

a lipid made up of glycerol joined to two fatty acids and a phosphate group; nonpolar hydrophobic tail and polar hydrophilic head

polymers

large molecule consisting of many identical or similar monomers linked together by covalent bonds

polypeptide

a polymer (chain) of amino acids linked by peptide bonds

polysaccharide

a carbohydrate polymer of many monosaccharides (sugars) linked by dehydration reactions

primary structure

the first level of protein structure; the specific sequence of amino acids making up a polypeptide chain

protein

a functional biological molecule consisting of one or more polypeptides folded into a specific three-dimensional structure

quaternary structure

the fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits

saturated fatty acid

a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds and the maximum number of hydrogen atoms are attached to the carbon skeleton; saturated fats and fatty acids solidify at room temp.

secondary structure

the second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain

starch

a storage polysaccharide in plants; a polymer of glucose

steroid

a type of lipid whose carbon skeleton is in the form of four fused rings with various chemical groups attached; ex: cholesterol, testosterone, estrogen

tertiary structure

third level of protein structure; the overall 3D shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain

trans fat

an unsaturated fat linked to health risks that is formed artificially during hydrogenation of vegetable oils

unsaturated fatty acid

a fatty acid that has one or more double bonds between carbons in the hydrocarbon tail and thus lacks the maximum number of hydrogen atoms. unsaturated fats and fatty acids do not solidify at room temp.

What kingdoms are found in the domain Eukarya?

Animalia, plantae, protista, fungi

What is the highest level of organization of life on Earth?

biosphere

Extremophiles, organisms that can live in environments where other organisms perish (such as boiling hot springs), belong to which of the 3 domains of life?

archaea

How is your reading this question an example of an emergent property of humans?

Interactions between both the eyes and the brain are required to read and understand a question

Does science seek truth, or does it seek understanding?

seek understanding

There are very few laws, but many theories in biology. Why?

Laws in science must be proven to be true. Theories are supported by repeated tests and evidence but cannot be proven true.

Creationism, the idea that the universe was created by a divine being, is not science and must not be taught as science because it fails which step of hypothesis-based science?

the testing step

What does it mean that a scientific hypothesis must be falsifiable?

It must be possible to devise an experiment that can prove the hypothesis is false.

Which elements are essential for life?

C, H, O, P, K, I, N, S, Ca, Fe, Mg, Na, Cl

Why is it necessary to have a fundamental understanding of chemistry in order to study biology?

All life functions depend on chemical reactions.

Why do oil and water not mix?

Oil is non-polar, and water is polar, and these two types of molecules do not mix.

Plants move water up their stems using a process called transpiration. Which property(s) of water contributes the most to the success of transpiration?

Water's cohesive and adhesive nature contribute the most to transpiration

Changing the temperature of water requires a tremendous amount of energy input compared to other substances, which is why a kettle on the stove becomes hot to the touch before the water inside it. The ability of a substance to resist temperature fluctuation is a measure of its \_______.

heat capacity

Water has a high heat capacity. Why is this fact important to life?

The high heat capacity of water stabilizes the Earth's climates and makes the planet hospitable