Cell Energy Test Review

Photosynthesis

Conversion of light energy from the sun into chemical energy.

cellular respiration

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

ATP

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

ADP

(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy

Redox reaction

A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.

Oxidation

loss of electrons

Reduction

gain of electrons

NAD+/NADH

electron carrier involved in glycolysis

NADP+/NADPH

in photosynthesis, the major electron carrier involved in electron transport

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.

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

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.

citric acid cycle

Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.

Chemiosmosis

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

substrate-level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

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 synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Fermentation

Process by which cells release energy in the absence of oxygen

lactic acid fermentation

the chemical breakdown of carbohydrates that produces lactic acid as the main end product

alcoholic fermentation

the anaerobic process by which yeasts and other microorganisms break down sugars to form carbon dioxide and ethanol

Anaerobic

Process that does not require oxygen

Aerobic

Process that requires oxygen

Autotroph

An organism that makes its own food

Heterotroph

An organism that cannot make its own food.

Photoautotrophs

Organisms that use light as a source of energy to synthesize organic substances.

Chemoautotrophs

Organisms that use hydrogen sulfide or other chemicals as energy source instead of light.

Chlorophyll

A green pigment found in the chloroplasts of plants, algae, and some bacteria

mesophyll

The ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis.

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

Stroma

fluid portion of the chloroplast; outside of the thylakoids

Thylakoid

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.

light reactions

The first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.

carbon fixation

The initial incorporation of carbon into organic compounds.

Wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Photon

a particle of light

Photosystem

cluster of chlorophyll and proteins found in thylakoids

pigment

Light-absorbing molecule

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.

Rubisco

The most abundant protein on earth. Performs Carbon Fixation in the Calvin Cycle.

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

mitochondrial matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.

mitochondria inner membrane

Folded into cristae. Contain enzymes for electron transport chain.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

grana

stacks of thylakoids

G3P

molecule that is made in the Calvin cycle; glucose is formed when two of these molecules combine

RuBP

ribulose biphosphate; a five-carbon carbohydrate that combines with CO2 to form two molecules of PGA in the first step of the Calvin Cylce

H+ concentration gradient

this drives the chemiosmosis which is used to make ATP

Photosynthesis equation

6CO2 + 6H2O + light energy --> C6H12O6 + 6O2

cellular respiration equation

C6H12O6+6O2---> 6CO2+6H2O+ATP