Biology Metabolism Exam 3

Acetyl CoA

the combination of an acetyl group derived from pyruvic acid and coenzyme A which is made from pantothenic acid (a B-group vitamin)

activation energy

Energy needed to get a reaction started

active site

enzyme's specific region to which the substrate binds

ADP

adenosine diphosphate a molecule that is involved in transferring and providing cells with energy

Aerobic

Process that requires oxygen

aerobic respiration

procees in which organisms convert in the presences of energy to oxygen

allosteric regulator

inhibition by a binding event at a site different from the active site, which induces a conformational change and reduces the enzyme's affinity for its substrate

allosteric site

A specific receptor site on some part of an enzyme molecule remote from the active site.

AMP

adenosine monophosphate, also known as 5'-adenylic acid, is a nucleotide. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine. It is an ester of phosphoric acid and the nucleoside adenosine.

Anaerobic

Process that does not require oxygen

anaerobic respiration

process in which organisms convert energy for their use in the absence of oxygen

antenna pigments

pigment molecule that directly absorbs light and transfers the energy absorbed to other pigment molecules

ATP

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

ATP synthase

a membrane-embedded protein complex that regenerates ATP from ADP with energy from protons diffusing through it

Autotrophs

Organisms that are able to make their own food

Calvin Cycle

light-independent reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugar

carbon fixation

process of converting inorganic CO2 gas into organic compounds

catalysis

A process by which a chemical agent called a catalyst selectively increases the rate of a reaction without being consumed by the reaction.

CH4

methane, is the simplest of saturated hydrocarbons with a chemical formula

chemical energy

A form of potential energy that is stored in chemical bonds between atoms that releases when those bonds are broken

Chemiosmosis

process in which there is a production of adenosine triphosphate (ATP) in cellular metabolism by the involvement of a proton gradient across a membrane

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Citrate

A compound that is an intermediate in the citric acid cycle (krebs cycle)

Citrate chelates (binds) calcium ions, preventing blood clotting and thus is an effective anticoagulant

CO2

Chemical formula for carbon dioxide

Coenzyme

small organic molecule, such as a vitamin or its derivative, which is required to enhance an enzyme's activity

competitive inhibitor

type of inhibition in which the inhibitor competes with the substrate molecule by binding to the enzyme's active site

concentration gradient

difference in the concentration of a substance from one location to another

Cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

cyclic photophosphorylation

The synthesis of ATP during photosynthesis, coupled to the cyclic passage of electrons to and from P700, the specialized form of chlorophyll a which is involved in photosystem I, using a series of carrier molecules.

cytochrome

group of reversibly oxidizable and reducible proteins that forms part of the electron transport chain between photosystem II and photosystem I

Cytosol

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.

dark reactions of photosynthesis

known as the Calvin-Benson cycle. CO2 is used to synthesize sugars

electron acceptor

A reactant that gains an electron and is reduced in a reduction-oxidation reaction.

electron transport chain

group of proteins between PSII and PSI that pass energized electrons and use the energy released by the electrons to move hydrogen ions against their concentration gradient into the thylakoid lumen

Endergonic

A chemical reaction that requires the input of energy in order to proceed.

Energy

The ability to do work or cause change

Entropy

a measure of the disorder of a system

Enzyme

A type of protein that speeds up a chemical reaction in a living thing

enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

Excited elctrons

When an electron temporarily occupies an energy state greater than its ground state

Exergonic

Chemical reactions that release energy, occur spontaneously

FADH

An energy carrier that transport less energy than NADH but more than ATP, he reduced form of flavin adenine dinucleotide

FADH2

Flavin adenine dinucleotide, A molecule that stores energy for harvest by the electron transport chain, Is a redox cofactor that is created during the Krebs cycle

Fermentation

process of regenerating NAD+ with either an inorganic or organic compound serving as the final electron acceptor; occurs in the absence of oxygen

Ferredoxin

In photosynthetic organisms, an iron- and sulfur-containing protein in the electron transport chain of photosystem I. Can transfer electrons to the enzyme NADP+ reductase, which catalyzes formation of NADPH.

FeS

encodes a cytoplasmic protein tyrosine kinase implicated in growth factor and cytokine receptor signaling

FMN

flavin mononucleotide, riboflavin phosphate, electron carrier, It is a biomolecule derived from vitamin B2 (riboflavin) through the catalytic activity of the enzyme riboflavin kinase

free energy

Gibbs free energy is the usable energy, or energy that is available to do work

Glucose

A simple sugar that is an important source of energy, C6H12O6

Glyceralhyde 3-Phosphate

GAPDH catalyzes the transformation of glyceraldehyde 3-phosphate to glycerate-1, 3-biphosphate, a process accompanied by the production of NADH

Glycolysis

the process of breaking glucose into two three-carbon molecules with the production of ATP and NADH

GTP

guanosine triphosphate, energy source in protein synthesis

Heterotrophs

Organisms that depend on other organisms for their food.

Holoenzyme

enzyme with its cofactor

inner chloroplast membrane

Contains enzymes needed to make glucose during photosynthesis. Encloses stroma (liquid) and thylakoid membranes.

inner mitochondrial membrane

The membrane of the mitochondria that is the site of electron transport and chemiosmosis.

intermediary metabolism

The entire set of cellular metabolic reactions

kinetic energy

the energy an object has due to its motion

Krebs Cycle (Citric Acid Cycle)

series of enzyme-catalyzed chemical reactions of central importance in all living cells for extraction of energy from carbohydrates

lactic acid

Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.

light harvesting

a complex of proteins associated with pigment molecules that captures light energy and transfers it to reaction-center pigments in a photosystem

light reactions of photosynthesis

The steps in photosynthesis that occur on the thylakoid membranes of the chloroplast and that convert solar energy to the chemical energy of ATP and NADPH, evolving oxygen in the process.

Matrix

Innermost compartment of the mitochondrion

mechanical energy

Kinetic or potential energy associated with the motion or position of an object

mineralized

the process by which organic material in the bones of dead animals is replaced by minerals from the surrounding rock, creating fossils

Mitichondria

cellular organelles responsible for carrying out cellular respiration, resulting in producing ATP, the cell's main energy-carrying molecule

mitochondrial intermembrane space

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

molecular oxygen

formed when two oxygen atoms are covalently bonded together, comes from life, photosynthesis in plants and algae

NAD+

(nicotinamide adenine dinucleotide) electron carrier involved in glycolysis

NADH

the reduced form of NAD+; an electron-carrying molecule that functions in cellular respiration

NADP+

carrier molecule that transfers high-energy electrons from chlorophyll to other molecules

NADPH

An electron carrier involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, which provides the high-energy electrons for the reduction of carbon dioxide to sugar in the Calvin cycle.

noncompetitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.

noncyclic photophosphorylation

The set of light-dependent reactions of the two plant photosystems, in which excited electrons are shuttled between the two photosystems producing a proton gradient that is used for the chemiosmotic synthesis of ATP. The electrons are used to reduce NADP to NADPH. Lost electrons are replaced by the oxidation of water producing O2.

outer chloroplast membrane

-separates the thylakoid from the cytoplasm

-regulates flow of materials into and out of the chloroplast

outer mitochondrial membrane

the membrane that separates the contents of the mitochondrion from the rest of the cell, creating a cellular compartment with the ideal conditions for aerobic respiration. highly permeable due to many large pores that allow for the passage of ions and small proteins

Oxidation

A chemical change in which a substance combines with oxygen, as when iron oxidizes, forming rust, The loss of electrons from a substance involved in a redox reaction.

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, using the process of chemiosmosis in the presence of oxygen

Phosphofructokinase

The enzyme that catalyzes the phosphorylation of fructose-6-phosphate to form fructose-1-6-bisphosphate in the third step of glycolysis. This is the main regulatory step of glycolysis. PFK is feedback-inhibited by ATP.

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 1 (PS1)

integral pigment and protein complex in thylakoid membranes that uses light energy to transport electrons from plastocyanin to NADP+ (which becomes reduced to NADPH in the process)

photosystem II (PS II)

One of two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center.

Phototrophs

organism capable of producing its own organic compounds from sunlight

Pi

a membrane phospholipid, can be reversibly phosphorylated at the 3, 4, and 5 positions of the inositol ring to generate seven phosphoinositides: phosphatidylinositol 3-phosphate (PI3P), phosphatidylinositol 4-phosphate (PI4P), phosphatidylinositol 5-phosphate (PI5P), phosphatidylinositol 3,4-?????????

plant-like photosynthesis

cyanobacteria, Plants are autotrophs, which means they produce their own food. They use the process of photosynthesis to transform water, sunlight, and carbon dioxide into oxygen, and simple sugars that the plant uses as fuel. These primary producers form the base of an ecosystem and fuel the next trophic levels??

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides

potential energy

energy type that has the potential to do work; stored energy

product

A substance produced in a chemical reaction

proton gradient

The product of the electron transport chain. A higher concentration of protons outside the inner membrane of the mitochondria than inside the membrane is the driving force behind ATP synthesis.

Protonmotive Force

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.

Pyruvate

three-carbon sugar that can be decarboxylated and oxidized to make acetyl CoA, which enters the citric acid cycle under aerobic conditions; the end product of glycolysis

quinone

Small, lipid-soluble, mobile electron carrier molecule found in the respiratory and photosynthetic electron-transport chains.

reaction center

complex of chlorophyll molecules and other organic molecules that is assembled around a special pair of chlorophyll molecules and a primary electron acceptor; capable of undergoing oxidation and reduction

redox

chemical reaction that consists of the coupling of an oxidation reaction and a reduction reaction

reduced cofactors

These compounds accept electrons during the oxidation of substrates. Energy is released when they are oxidized, NADH and FADH2

reduction

gain of electrons by an atom or molecule

Respiration

The process by which cells break down simple food molecules to release the energy they contain.

ribulose bisphosphate

(RuBP) a five carbon sugar, which CO2 is incorporated into, during the first step of the calvin cycle

split water

an enzymatic reaction during photosynthesis that pulls the hydrogen atoms from water to produce O2 and H+ plus an electron

Stroma

fluid-filled space surrounding the grana inside a chloroplast where the light-independent reactions of photosynthesis take place