Shared Flashcard Set

Details

BIO Chapter 9
Definitions
24
Biology
Graduate
02/15/2012

Additional Biology Flashcards

 


 

Cards

Term
acetyl CoA
Definition
Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.
Term
aerobic respiration
Definition
A catabolic pathway for organic molecules, using oxygen (O2) as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukaryotic cells and many prokaryotic organisms.
Term
alcohol fermentation
Definition
Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide.
Term
ATP synthase
Definition
A complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membranes of eukaryotic cells and in the plasma membranes of prokaryotes.
Term
beta oxidation
Definition
A metabolic sequence that breaks fatty acids down to two-carbon fragments that enter the citric acid cycle as acetyl CoA.
Term
cellular respiration
Definition
The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP.
Term
chemiosmosis
Definition
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis.
Term
citric acid cycle
Definition
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration.
Term
cytochrome
Definition
An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells.
Term
electron transport chain
Definition
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP.
Term
facultative anaerobe
Definition
An organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present.
Term
glycolysis
Definition
A series of reactions that ultimately splits glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.
Term
lactic acid fermentation
Definition
Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+ with no release of carbon dioxide.
Term
NAD+
Definition
Nicotinamide adenine dinucleotide, a coenzyme that cycles easily between oxidized (NAD+) and reduced (NADH) states, thus acting as an electron carrier.
Term
obligate anaerobe
Definition
An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.
Term
proton-motive force
Definition
The potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen ions (H+) across a biological membrane during chemiosmosis.
Term
redox reaction
Definition
A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another; short for reduction-oxidation reaction.
Term
reducing agent
Definition
The electron donor in a redox reaction.
Term
reduction
Definition
The complete or partial addition of electrons to a substance involved in a redox reaction.
Term
substrate-level phosphorylation
Definition
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
Term
aero-
Definition
air (aerobic: chemical reaction using oxygen)
Term
an-
Definition
not (anaerobic: chemical reaction not using oxygen)
Term
chemi-
Definition
chemical (chemiosmosis: the production of ATP using the energy of hydrogen ion gradients across membranes to phosphorylate ADP)
Term
glyco-
Definition
sweet; -lysis = split (glycolysis: the splitting of glucose into pyruvate)
Supporting users have an ad free experience!