AP Biology Unit 3 Review

acetyl coA

Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP; located in the inner membrane of mitochondria and the thylakoid membrane of chloroplasts

Calvin cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build sugars; occurs in the stroma of chloroplasts

cellular respiration

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

chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

chlorophyll

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

chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

citric acid/Krebs cycle

A series of eight chemical reactions that starts with citrate (citric acid, when protonated) and ends with oxaloacetate, which reacts with acetyl CoA to form citrate—forming a cycle that is part of the pathway that oxidizes glucose to CO2.

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.

fermentation

occurs in the cytoplasm and regenerates the cell's supply of NAD+ while producing a small amount of ATP

glycolysis

A metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP

light dependent reactions

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

mitochondrion

Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use

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.

photolysis

In the thylakoid membranes of a chloroplast during light-dependent reactions, two molecules of water are split to form oxygen, hydrogen ions, and electrons.

photosynthesis

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

photosystem I

One of two light-harvesting units of a chloroplast's thylakoid membrane; it uses the P700 reaction-center chlorophyll.

photosystem II

One of two light-harvesting units of a chloroplast's thylakoid membrane; it uses the P680 reaction-center chlorophyll.

pyruvate

Organic compound with a backbone of three carbon atoms. Two molecules form as end products of glycolysis

stroma

fluid portion of the chloroplast; outside of the thylakoids

substrate-level phosphorylation

The formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.

thylakoid membrane

The photosynthetic membrane within a chloroplast that contains light gathering pigment molecules and electron transport chains.

oxidation

loss of electrons

reduction

gain of electrons

cytoplasm

location of glycolysis and fermentation

final electron acceptor in ETC of cellular respiration

oxygen

products of glycolysis

2 pyruvate, 2 ATP, 2 NADH

inner mitochondrial membrane

location of the ETC in cellular respiration

mitochondrial intermembrane space

The space between the inner and outer membranes of the mitochondria that has a high H+ concentration.

proton gradient

The product of the electron transport chain. A higher concentration of protons in the intermembrane space of the mitochondria than in the mitochondrial matrix is the driving force behind ATP synthesis.

products of the light reactions

ATP, NADPH, oxygen