Bio H Midterms

Activation Energy

Activation Energy

Energy needed to get a reaction started

Adenosine Triphosphate (ATP)

compound used by cells to store and release energy

Aerobic Respiration

Respiration that requires oxygen

Alcohol Fermentation

Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide.

Amine Group

Contains nitrogen bonded to two hydrogen atoms

Amino Acid

compound with an amino group on one end and a carboxyl group on the other end

Anabolic

A process in which large molecules are built from small molecules

Anaerobic Respiration

Respiration that does not require oxygen

Atom

Smallest particle of an element

Carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; short term energy

Carbon Dioxide

CO2

Carboxyl group

A functional group present in organic acids and consisting of a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group.

Catabolic

A process in which large molecules are broken down

Catalyst

substance that speeds up the rate of a chemical reaction

Cellular Respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Chemical Bond

the attractive force that holds atoms or ions together

Chemical Energy

potential energy stored in chemical bonds

Covalent Bond

a bond formed when atoms share one or more pairs of electrons

Dehydration Synthesis

a chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule

Electron

negatively charged particle

Electron Transport Chain

a series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP into ATP

Element

pure substance that consists entirely of one type of atom

Enzyme

protein that acts as a biological catalyst

Fermentation

a reaction that makes ATP without oxygen

Glucose

C6H12O6

Glycolysis

the first step in cellular respiration, where glucose is broken down into pyruvate

Homeostasis

process by which organisms maintain a relatively stable internal environment

Hydrogen Bond

weak bond between a hydrogen atom and another atom

Hydrolysis

a chemical process that splits a molecule by adding water.

Hydroxyl group

-OH

Ionic Bond

a bond formed when electrons are transferred from one atom to another

Isotope

atoms with the same amount of protons but different amount of neutrons

Isomer

compounds with the same chemical formula but different structures

Krebs Cycle

second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

lactic acid fermentation

A series of anaerobic chemical reactions using pyruvic acid that supplies energy when oxygen is scarce

Law of Conservation of Energy

energy cannot be created or destroyed, it can only change forms

Law of Conservation of Matter

Matter cannot be created or destroyed

Lipids

macromolecule made from carbon, oxygen, and hydrogen atoms; long term energy

Macromolecule

A very large organic molecule composed of many smaller molecules

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

mitochondria

Organelle that is the site of ATP (energy) production

Molecular Formula

A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

Molecular Structure

the three-dimensional arrangement of atoms in a molecule

Monomer

A simple compound whose molecules can join together to form polymers

Monosaccharide

A simple sugar molecule (ex. glucose or fructose)

NADH, NAD+

electron carriers in cellular respiration

negative feedback mechanism

causes a system to change in the opposite direction from which a stimulus is moving it

Neutron

A subatomic particle that has no charge and is found in the nucleus of an atom

Nucleic acid

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus; polymer of nucleotides

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base

Organic

Contains carbon

Output

The results of the operation of any system.

Oxidation

The loss of electrons from a substance involved in a redox reaction.

Polymer

A long molecule consisting of many monomers linked together.

Polysaccharide

large macromolecule formed from monosaccharides

Primary Structure

the specific sequence of amino acids making up a polypeptide chain.

Product

A substance produced in a chemical reaction

Protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

Proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

Pyruvate

Three-carbon compound that forms as an end product of glycolysis.

Quaternary Structure

the shape resulting from the association of two or more polypeptide subunits.

R Group

a functional group that defines a particular amino acid and gives it special properties.

Reactant

a substance that takes part in and undergoes change during a reaction.

Reduction

gain of electrons

Response

a reaction to a stimulus

Secondary Structure

the coils or folds of a polypeptide chain.

Stimulus

a signal to which an organism responds

Substrate

reactant of an enzyme-catalyzed reaction

Tertiary Structure

the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

Thermoregulation

Process of maintaining an internal temperature within a tolerable range.

Valence shell

outermost electron shell

Valence electron

Electrons on the outermost level of an atom

Nitrogenous bases in DNA

adenine, guanine, cytosine, thymine

oxygen debt

the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose

Abiotic

Non-living

Atmosphere

A mixture of gases that surrounds a planet

autotrophs

Organisms that make their own food

biogeochemical cycle

the movements of matter within and between ecosystems

biomass

the total mass of organisms in a given area or volume.

biotic

living

Calvin Cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build sugars

carbon cycle

the movement of carbon from the nonliving environment into living things and back

carrying capacity

Largest number of individuals of a population that a environment can support

Chlorophyll

Green pigment in plants that absorbs light energy used to carry out photosynthesis

Chloroplast

Site of photosynthesis

Consumer

An organism that obtains energy by feeding on other organisms

Decomposer

An organism that breaks down wastes and dead organisms

Ecosystem

A biological community of interacting organisms and their physical environment.

energy pyramid

shows the amount of energy in an ecosystem moves from one trophic level to another

food chain

series of steps in an ecosystem in which organisms transfer energy by eating and being eaten

food web

several interrelated food chains

fossil fuels

a natural fuel formed from the remains of living organisms.

greenhouse effect

Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases

Heterotroph

organism that obtains energy from the foods it consumes

light energy

Energy in the form of moving waves of light

light reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

photon

a particle of light

Photosynthesis

process by which some organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

Photosynthesis equation

6CO2 + 6H2O > C6H12O6 + 6O2

primary producers

the first producers of energy-rich compounds that are later used by other organisms