Bio 150: Microbiology: Chapter 8: Microbial Metabolism

Move the terms into the correct empty boxes to complete this concept map comparing cellular metabolism in bacteria and eukaryotes.

(from left to right) bacteria, eukaryotes glycolysis, electron transport system, krebs cycle cell membrane, mitochondrial matrix, inner mitochondrial membrane periplasmic space, intermembrane space

Label the image to review how catabolic and anabolic reactions intersect in the metabolism of carbohydrate and non-carbohydrate compounds.

(from top left to right): anabolism, chromosomes, enzymes, cellulose, lipids, catabolism, deamination, glucose, beta oxidation, pyrovate, acytl coA

Place the steps in the correct order to review the process of enzyme repression.

(starting from the yellow squiggly line) 1. RNA is translated 2. protein 3. functional enzyme 4. substrate 5. excess product binds DNA 6. DNA is transcribed in the middle: DNA is not transcribed

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

activating the gene responsible for a particular enzyme

the ______ site is the region on an enzyme that binds substrate

active (catalytic)

in competitive inhibition, the molecular mimic competes for the ________ of an enzyme

active site

The electron transport chain is part of ______.

aerobic respiration

anabolism

any process that results in synthesis of cell molecules and structures

Which of these represents a proton? Cytochrome Hydrogen ion Carbon atom Oxygen ion

b

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

a(n) ______ is a biological cataylst

enzyme

a(n) ________ describes any enzyme that works outside a cell in which it was produced

exoenzyme

In bacteria, the electron transport chain is located

in the plasma membrae

Enzyme _________ is a type of control on enzyme synthesis where enzymes are made only when suitable substrates are present.

induction

Label the figure to review the various patterns of metabolism exhibited by biological cells.

linear: pink cyclic: light green branched: orange -divergent: light orange -convergent: dark yellow

which model is sometimes used to describe enzyme-substrate interactions?

lock-and-key

the location of the Krebs cycle enzymes in eukaryotes is in the ______ matrix, while in prokaryotes the enzymes are found in the _______

mitochondrial cytosol

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

Glycolysis starts with _____ and ends with _____

one glucose; two pyruvate molecules

Hydrogen consists of ______.

one proton and one electron

in a redox reaction, one compound is _______ and another compound is ______

oxidized reduced

the enzyme that catalyzes this reaction of the Krebs cycle is best described as a(n):

oxioreductase

in noncompetitive inhibition, the molecular mimic competes for the _____ of an enzyme

regulatory site

Coenzyme Q

transfers protons from inside the membrane to outside the membrane.

The last carrier protein in the electron transport chain transfers

two electrons to oxygen.

which definition best describes "oxidation"? when a compound LOSES electrons to an electron-accepting compound or when a compound GAINS electrons from an electron-donating compound

when a compound LOSES electrons to an electron-accepting compound

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

apoenzyme

in a metabolic pathway, ______ and _____ multiple enzymes compete for a single substrate branches provide alternate methods for nutrient processing enzymes are bonded to one another covalently the product of one reaction is often the substrate for another

branches provide alternate methods for nutrient processing the product of one reaction is often the substrate for another

which can act as an electron carrier

coenzymes

which 3 of the following are characteristics of most enzymes?

composed of protein lower the activation energy for a reaction are much larger in size than their substrate

what name is used to describe enzymes that are generally found at constant amounts in the cell independent of substrate concentrations?

constitutive enzymes

Noncompetitive inhibition

enzyme regulation due to the binding of molecules other than the substrate in the regulatory site

what is a term used to describe a catabolic pathway where the end product inhibits the pathway?

enzyme repression

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

faster

Competitive inhibition

inhibition of enzyme activity by supplying a molecule that resembles the enzyme's normal substrate

the enzyme that catalyzes this Krebs cycle reaction is best described as a(n) ______

isomerase

which term describes the compound that GAINS electrons from an electron-donating compound?

reduced

Which suffix denotes an enzyme?

-ase

Label the image to test your understanding of the most common pathways of glucose metabolism.

1. aerobic respiration: 36-38 ATP 2. anaerobic respiration: 2-36 ATP 3. fermentation: 2 ATP

Photophosohorylation

1. light-driven redox reactions in the thylakoid membrane 2. H+ is pumped to the inner chamber of the grana creating a proton motive force

Substrate-level phosphorylation

1. phosphate group transferred to ADP directly from an organic molecule 2. energy to add P to ADP derived from breaking a high energy phosphate bond

how many bonds must be broken to form AMP from ATP?

2

During the electron transport chain, ATP will be made from ______.

ADP + Pi

NAD is reduced to _______ in the prepatory reactions preceding the Krebs cycle

NADH

What is a by-product of the Krebs cycle?

CO2

Which of the following contain a metal ion which can accept and donate electrons?

Cytochromes

T/F: Only yeast are able to carry out fermentation for catabolism.

F

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

F

Hydrogens are transported from other reactions to the electron transport chain by ______.

NADH and FADH

aerobic respiration includes the following 3 pathways

Krebs cycle respiratory chain glycolysis

Drag and drop the labels into the correct empty boxes to complete the concept map.

Metabolism: Catabolism, Anabolism. depends on biological catalysts, called enzymes, act on substrates to produce products. enzymes lower activation energy. enzyme rate is affected by temperature and pH

common electron barriers include

NAD FAD

T/F: enzyme induction is genetically controlled

T

T/F: typically, cool temperatures do not denature enzymes the way heat does

T

How is anaerobic respiration different from aerobic respiration?

The final electron acceptor

Complete the sentences to test your understanding of respiration and fermentation. Then, arrange the sentences into a logical paragraph.

The processes of aerobic and anaerobic respiration, as well as fermentation, all begin with glycolysis. Glycolysis occurs in the cytoplasm and overall generates 2 ATP. The two molecules of pyruvate produced in glycolysis can be turned into acids and other products through fermentation. In other microbes, the process of respiration continues when pyruvate is utilized in a set of reactions called the Krebs cycle. The Krebs cycle produces a small amount of ATP, but also generates the reduced carriers NADH and FADH₂. These molecules then bring the electrons generated by glycolysis and the Krebs cycle to the electron transport system embedded in the bacterial cell membrane. Cell that conduct aerobic respiration utilize free oxygen as a final electron acceptor in this process, while those that conduct anaerobic respiration use oxygen-containing ions to create ATP molecules.

vitamin deficiency results in the inability to form ______

a complete holozenzyme

The energy for the synthesis of ATP in the electron transport chain is provided by _____.

a proton gradient

The electron carrier proteins in the electron transport chain shuttle electrons to

a terminal acceptor

where can an enzyme work

both inside and outside the cell in which the enzyme was produced

The NADH involved in the electron transport chain is made

by redox reactions in glycolysis and the Krebs cycle.

ribozymes ____ and _____

can inhibit gene expression may have served as the first genetic material within ancient cells

which is NOT a method of overcoming activation energy in any reaction

decreasing the substrate concentration

The loss of the normal or native shape of a protein due to chemical or physical disruption of tertiary structure is called protein __________.

denaturation

what term is used to describe enzymes which work within the cell that produces them?

endoenzyme

match each enzyme class with the enzyme function oxioreductase transferase hydrolase lyase isomerase ligase -form bonds using water and the energy in ATP -cleave bonds with the addition of water -transfer functional groups from one substrate to another -transfer electrons from one substrate to another -add or remove groups from double bonded substrates -convert a substrate to its isomeric form

oxioreductase-transfer electrons from one substrate to another transferase-transfer functional group from one substrate to another hydrolase-cleave bonds on molecules with the addition of water lyase-add groups to or remove groups from double-bonded substrates isomerase-change a substrate into its isomeric form ligase-catalyze the formation of bonds with the input of ATP and the removal of water

What is reduced at the end of the electron transport system?

oxygen

In this reaction, ATP synthase uses energy from ______ to make ATP.

protons re-entering the cell

catabolism

reactions that break the bonds of larger molecules into smaller molecules

During the electron transport chain in bacteria, protons are

shuttled to the outside of the cell membrane.

regulated enzymes are induced according to the concentration of which of the following?

substrate

the _____ is the term for a specific molecule on which an enzyme acts

substrate

Oxidative phosphorylation

1. series of redox reactions in the final stage of respiration 2. takes place in the cyctoplasmic or inner mitochondrial membranes

What is the total ATP yield per glucose in organisms that carry out fermentation?

2

How much ATP is generated in the electron transport system?

30

During glycolysis, ______ is oxidized and ______ is reduced.

Glucose; NAD+

What is oxidized at the beginning of the electron transport system?

NADH and FADH2

Move the terms into the correct empty boxes to complete the concept map.

Products are made from substrates with the help of enzymes, can be protein and RNA, acts as catalysts that affects the rate and the ability to reach the energy of activation, enzymes are also influenced by pH and temperature

What serves as an electron acceptor in fermentation?

Pyruvate or other organic molecule

Where do the electrons for the electron transport system come from?

Reduced coenzymes

What is the main purpose for fermentation reactions?

Regenerate NAD molecules for glycolysis

which 2 of the following are correct about the catalytic function of enzymes

an enzyme binds to its substrate an enzyme participates in changes to the substrate

electron carriers like NAD and FAD repeatedly _______

accept and release electrons

What two main types of by-products are produced in fermentation?

acids, alcohol

the minimum amount of energy required for a reaction to proceed is termed the ______ energy

activation

Proton pumps are an example of _____ transport

active

which feature of an enzyme is the "most" unique?

active site

metabolism

all chemical reactions of the cell

Constitutive enzyme

always present in relatively constant amounts regardless of the amount of substrate

to increase concentration of an induced enzyme:

genes must be expressed or induced

Label the image to test your understanding of the cellular reactions involved in metabolism.

glucose, precursor molecules, building blocks, macromolecules, cells, catabolism (yields energy), anabolism (use energy)