Chapter 8. Microbial Metabolism: The Chemical Crossroads of Life

electron carriers

- accept and release electrons - become reduced when they receive electrons

To increase concentration of an induced enzyme.....

...genes must be expressed or induced

which three of the following are characteristics of most enzymes:

1- have a unique shape and specificity 2- act as organic catalysts 3- function in low concentration - are larger in size than their substrates - lower the activation energy for a reason - composed of protein

How many ATP molecules are produced by oxidative phosphorylation for each glucose that enters glycolysis?

34

A total of ______ ATP are generated from substrate level phosphorylation of one molecule of glucose in glycolysis, though 2 are spent in the process itself.

4

Which is NOT a common coenzyme carrier in cells? - NADP - ADP - NAD - FAD

ADP

vitamin deficiency results in the inability to form

a complete holoenzyme

the word "induction" when used to describe "enzyme induction" is in reference to

activating the gene responsible for a particular enzyme

Term used to describe the minimum amount of energy required for a reaction to proceed?

activation energy OR energy of activation

The _________ site is the region on an enzyme that binds substrate.

active

the two general types of fermentation products:

alcoholic and acidic

ATP synthase is principally composed of _______.

amino acids

The letters in ATP represent the words

andenosine triphosphate

What term refers to a biological catalyst that lacks an essential cofactor?

apoenzyme

an enzyme acts as a that alters the rate of a reaction without being changed by the reaction

catalyst

The active site of an enzyme is also known as the _______ site.

catalytic

The release of electrons to power the pumping of hydrogen which generates a concentration gradient to power ATP synthesis is called _____.

chemi-osmosis

Which of the following can act as an electron carrier?

coenzymes

Which of the following represent cofactors?

coenzymes & metal ions

Which identifies the correct relationship among components of coenzymes?

coenzymes = organic / Metals = inorganic

Often, _________ will bind within an enzyme's active site and produce a unique active site for the substrate.

cofactors

when a molecular mimic competes with the normal substrate for the active site of an enzyme, the enzyme is effectively shut down. This form of inhibition is termed __________ inhibition.

competitive

________ enzyme describes an enzyme present in constant amounts regardless of the presence of substrate

constitutive

Identify the reactants in the terminal step of aerobic respiration, catalyzed by cytochrome oxidase. - (choose 3) - carbon dioxide - electrons - reduced cofactors - water - oxygen - protons

electrons, oxygen, protons

a reaction that consumes energy is termed:

endergonic

_________ describes any enzyme that works WITHIN a cell in which it was produced

endoenzyme

_________ describes any enzyme that works OUTSIDE a cell in which it was produced

exoenzyme

T/F: Most enzymes are named based on their molecular composition.

false

in the presence of an enzyme catalyst, a chemical reaction will proceed ___________ than if the enzyme were not present.

faster

fats are composed of ____________ acids linked by glycerol compounds

fatty

which four of the following would increase the rate of an enzyme reaction which is currently not at optimal conditions

increase substrate(s) concentration, increase temperature slightly, decrease temperature slightly, increase enzyme concentration

ATP contains ___ phosphate groups, while ADP has two.

three

T/F: An enzyme's active site is unique for each substrate.

true

T/F: Autotrophs can synthesize all macromolecules from carbon dioxide and minerals.

true

T/F: Typically, cool temperatures do not denature enzymes to the same extent as heat does.

true

The final step in the electron transport chain produces....

water

the specific process of _________ incorporates nutrients through biosynthesis in cells

Anabolism

Why are fatty acids a good place to store energy?

Because you can oxidize the carbons on them

Where can an enzyme work?

Both inside or outside the cell in which the enzyme was produced

_______________ refers to the decomposition of complex organic compounds during cellular metabolism

Catabolism

What term is used to describe proteins losing their 3D structure as a consequence of changes in the environmental conditions such as excessive heat or salt?

Denaturation

_________ reactions are those reactions that release energy as the reaction proceeds

Exergonic

The ______ ________ is the only cellular respiration pathway which generates FADH as one of many products

Krebs cycle

a chemical compound that is the source of another compound is referred to as a(n) ___________.

precursor

What breaks down fatty acids?

Lipase

What term describes the compound which LOSES electrons to an electron-accepting compound?

Oxidized

What term describes the compound which GAINS electronics from an electron-donating compound?

Reduced

Regulated enzymes are induced or repressed according to the concentration of which of the following? - Inhibitors - Substrate - Enzyme

Substrate

the electron transport chain is located in the __________ membrane of eukaryotic cells and _____________ membrane of bacteria

inner mitochondrial; plasma

Which pathway other than glycolysis would you expect an amphibolic reaction to begin?

kerbs cycle

Which model describes enzyme-substrate interactions? - antigen-antibody complex - fluid mosaic - lock-and-key

lock-and-key

Enzymes can have _______ active site(s).

multiple

when a molecule binds to the regulatory site of an enzyme, the enzyme is effectively shut down. This form of inhibition is termed __________ inhibition.

noncompetitive

A redox reaction involves the coupling of which 2 types of reactions?

oxidation and reduction

A series of metabolic reactions is termed.....

pathway

Which components contribute to the structure of ATP? - ribose - phosphate - glucose - adenine - thymine - phenol

phosphate, adenine and ribose

what name is given to an enzyme that can break down proteins to basic component parts?

protease

by the end of glycolysis, glucose is converted into 2, 3-carbon _______ _______ molecules

pyruvic acid

In noncompetitive inhibition, the molecular mimic competes for the __________ of an enzyme

regulatory site

The inhibition of enzyme synthesis by the end product of a catabolic pathway occurs in enzyme _____.

repression

Aerobic respiration includes the following three pathways:

respiratory chain, glycolysis, krebs cycle

___________ are a class of RNA molecules that catalyze reactions on other RNA, and their discovery serves as evidence to support the RNA hypothesis

ribozymes

In cells, the biosynthesis of carbohydrates involves:

several alternative pathways

Regulated enzyme actively is completely dependent on _________ concentration

substrate

What name is given to the compound which an enzyme will act upon?

substrate