cellular respiration Flashcards
Forms of energy
kinetic and potential
Metabolic pathways
a series of enzymatic reactions that converts one biological material to another.
Anabolism
Metabolic pathways that construct molecules, requiring energy.
Catabolism
Metabolic pathways that break down molecules, releasing energy.
free energy
energy that is available to do work
energy coupling reaction
the use of energy released from exergonic reactions to drive essential endergonic reaction.
enzyme
A type of protein that speeds up a chemical reaction in a living thing
Cofactors
Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis
coenzyme
small carbon containing molecules which are not permanently bound to the enzyme, and must collide with the enzyme and bind to it’s active site before the catalytic reaction occurs.
prosthetic group
A cofactor or coenzyme that is covalently bonded to a protein to permit its function
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
Structure of ATP
adenine, ribose, 3 phosphate groups
What releases energy in ATP
hydrolysis
substrate-level phosphorylation
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
Chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.
oxidative phosphorylation
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.
Photophosphorylation
The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis.
Oxidation
loss of electrons
reduction
gain of electrons
Aerobe
Organism that can grow in the presence of atmospheric oxygen.
Anaerobe
any organism that is able to live without oxygen
cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
Mitochondria structure
outer membrane, inner membrane, intermembrane space, matrix, cristae
Four stages of aerobic respiration
glycolysis, formation of acetyl coenzyme A, citric acid cycle/ Krebs cycle, electron transport and chemiosmosis
Glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
two phases of glycolysis
energy investment phase and energy payoff phase
Glycolysis produces
2 ATP, 2 NADH, 2 pyruvate
Formation of Acetyl CoA
coenzyme-A attaches to NADH
Krebs Cycle (Citric Acid Cycle)
second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
Where does glycolysis occur?
cytoplasm
Where does the Krebs cycle occur?
mitochondrial matrix
The Krebs cycle produces
2ATP, 6NADH, and 2FADH
What molecules carry the most energy
NADH and FADH2
electron transport chain
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
Where does the electron transport chain occur?
inner membrane of mitochondria
ATP synthase
Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
Aerobic Respiration yields
36-38 ATP
pyruvate formation yields
2 NADH
Krebs cycle yields
6 NADH, 2 FADH2, 2 ATP
Fermentation
A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
functions of fermentation
- It is an inefficient way to use fuel
- It allows organisms to survive without oxygen
- It removes toxic excess NADH in the cytosol
- It replenishes the supply of NAD+
Autotroph
An organism that makes its own food
Heterotroph
An organism that cannot make its own food.
Phototrophs
obtain energy from light
Chemotrophs
Organisms that get energy from chemicals taken from the environment
Photoautotrophs
Organisms that use light as a source of energy to synthesize organic substances.
