Microbiology Exam 3 Study Guide

Category of metabolism that builds covalent bonds

Anabolism

Category of metabolism that breaks covalent bonds via hydrolytic reactions

Catabolism

More energy consumed than produced, requires ATP. Associated with anabolism

Endergonic

More energy released than produced, makes ATP. Associated with catabolism.

Exergonic

Protein synthesis and DNA replication are examples of

AnabolismA diss

A disaccharide like lactose being broken into smaller parts is an example of

Catabolism

How many phosphate groups does ATP contain?

Three

Phosphate groups have what kind of charge?

Negative

The highest energy bond in a phosphate group is called the

Terminal Phosphate Group

Terminal phosphate groups are what from other molecules in the ATP structure?

Furthest

ATP bonds that when broken release more energy than most and take more energy than most to build

High energy bonds

What is ATP’s relationship to RNA?

RNA nucleotide that builds RNA

ATP's nitrogen containing base

Adenine

ATP’s five carbon sugar

Ribose

ADP has how many phosphate groups?

Two

Exergonic process that breaks ATP into ADP to release energy for cellular work

Hydrolysis

Connects phosphate group furthest from the rest of the molecules to go from ADP to ATP

Terminal phosphate bond

Endergonic process that joins ADP with an additional phosphate group to create ATP to be used later for cellular work

Synthesis

Metabolic processes that produce ATP

Respiration and Fermentation

Molecules that are made along the way of a metabolic pathway that are not the starting or finishing point

Intermediates

Does a metabolic pathwway take one or multiple steps?

Multiple

Enzymes always consist of …, but may also be made of other things in addition

Proteins

Proteins that catalyze (speed up) biochemical reactions without being permanently altered and are used in nearly all cellular reactions. Some may also consist of RNA.

Enzymes

Example of a pathogen which is also an enzyme

Botulism toxin

Process that causes an enzyme to lose its 3D shape and cease functioning

Denaturation

Examples of things that can cause denaturation

Heat, Chemicals, Salt, Extreme pH

Suffix that many enzymes end in

-ase

Sucrose, a disaccharide, is the substrate in a reaction. It joins with water, which breaks it down into two monosaccharides. The products of this reaction are two glucose molecules. What kind of reaction is this?

Catabolism

Substance acted on by an enzyme. Sometimes called a “reactant”.

Substrate

Region of an enzyme that interacts with the substrate. Usually a depression on the enzyme’s surface. Uses induced fit rather than lock and key.

Active site

Enzymes are picky and only work with specific substrates. This is known as

Specificity

Enzymes located outside a cell

Exoenzymes

Enzymes located within a cell

Endoenzymes

A enzyme returns to its original shape after

product is released

Do substrates and products permanently change shape after being used for a reaction?

Yes

What makes enzymes so efficient?

They are reusable

What is the goal of enzymes and how do they achieve it?

Speed up reactions by lowering activation energy

Energy needed to start a reaction

Activation energy

If an enzyme contains both proteins and attached cofactors it is known as

Conjugated

Whole active enzymes

Holoenzyme

Inactive protein portion of an enzyme

Apoenzyme

Non-protein portion of a conjugated enzyme

Cofactor

Cofactors can be … or …

metal ions or coenzymes

Inorganic cofactors that form a bridge between substrate and enzyme

Ions

Fe2+, Zn2+, Mg2+ and Ca2+ are examples of

Ions

NADH/NAD+ and FADH2/FAD are examples of …

Coenzymes

Organic cofactors that remove a chemical group from one substrate and transfer it to another. Generally more complex than their counterparts.

Coenzymes

How fast an enzyme converts substrate to product. Affected by temperature. pH, substrate concentration, and presence of inhibitors

Enzyme activity

Increased temperature increases enzyme activity, but past optimal temperature can also cause denaturation that may be reversible. What is the optimal temperature for most pathogens?

35 - 40 C

If pH becomes too acidic or basic, denaturation occurs. When this happens, H+ and OH- molecules will compete with ions in what kind of bond?

Ionic

When there is more substrate available than active sites, production will plateau. This is known as

Saturation

Why can a slight fever be beneficial for somebody with a bacterial infection?

Proteins are denatured to slow bacterial enzyme activity

Enzyme activity will always increase as substrate concentration increases.

False

Inhibitor that binds to an active site to block it from the substrate, preventing product from being made. Must have a similar shape tp the substrate to fit into the active site.

Competitive

Inhibitor that binds to an allosteric site and causes the enzyme (including the active site) to change shape, preventing the substrate from fitting.

Allosteric

Allosteric inhibitors are also known as

Non-competitive

Beta lactam drugs , sulfa drugs, and some antibiotics work via

Competitive inhibition

What charge does an electron have?

Negative

If a molecule gains 1 or more electrons, its overall charge would be

Reduced

FE+3 is an iron ion. Ions contain more protons than neutrons. If FE+3 gains an electron, it will become FE+2. What kind of reaction is this?

Reduction

Reaction that involves a loss of electrons (or H+)

Oxidation

Reaction that involves gain of electrons (or H+)

Reduction

A dehydrogenation reaction sees the removal of a hydrogen atom (which includes its electrons). therefore4, dehyrdogenation is what kind of reaction?

Oxidation

Of the pair of coenzymes NAD+ and NADH, which is the reduced form?

NADH

Between NADH and NAD+, which is a better receiver of electrons?

NAD+

When NAD+ turns into NADH, what has happened to it?

Reduction

What are the oxidized forms of the coenzymes NADH and FADH2?

NAD+ and FAD

What is the function of NAD+/NADH and FAD/FADH2?

Coenzymes that shuttle electrons within the cell.

Empty shuttle that picks up electrons

Oxidized coenzymes

Full shuttle that drops of electrons

Reduced coenzymes

Form of a coenzyme that is electron poor

Oxidized

Form of a coenzyme that is electron rich

Reduced

Oxidation and reduction reactions are known as what type of reaction?

Redox

Redox reactions cannot occur independently because they need both a donor and recipient to transfer electrons. This means that they are

coupled

Cell respiration and fermentation are metabolic pathways that … external chemical energy sources like …

oxidize, glucose

Molecular formula of glucose

C6H12O6

Glucose is electron rich making it a good

energy source

Goal of metabolic pathways like respiration and fermentation

Make ATP

In addition to sugars like glucose, metabolic pathways can also utilize … or … to make ATP

proteins, fats

H is a hydrogen … which is … and contains one proton (H+) and one electron

atom, neutral

H+ is a hydrogen … (an H atom which has lost an electron) and is essentially a …

ion, proton

The final molecule to receive electrons in an electron transport chain during cellular respiration

Terminal electron acceptor

In cellular respiration, a terminal electron acceptor is ultimately

reduced

In an electron transport chain, O2 is the terminal electron acceptor. This means the cell respires

aerobically

In an electron transport chain, a moleceule other than O2 is the terminal electron acceptor. This means the cell respires

anaerobically

O2 is the formula for

molecular oxygen

In the reaction 6O2 + C6H12O6 → 6CO2 + 6H2O + ATP glucose undergoes a(n) … to form 6CO2. O2 undergoes a(n) … to form 6H2O. Is this reaction anabolic (A) or catabolic (B)? This summary reaction describes cell respiration when … is the energy source and … is the terminal electron acceptor.

oxidation, reduction, B, glucose, oxygen

Glycolysis and the Krebs cycle together form

central metabolism

Cell respiration requires a … and a …

chemical energy source, terminal electron acceptor

In eukaryotes, … are used for the Krebs cycle

mitochondria

In prokaryotes, … and … are used for the Krebs cycle

cytoplasm, plasma membrane

In the aerobic respiration of glucose, glucose provides … that move through the … which generates an … gradient that fuels … synthesis.

electrons, electron transport chain, H+, ATP

In the aerobic respiration of glucose, the yield is … ATPs from central metabolism and … ATPs from chemiosmosis for a total of … ATPs.

4, 34, 38

In the aerobic respiration of glucose, glycolysis breaks down glucose into 2 …, yielding … net ATPs and … NADHs.

pyruvates, 2, 2

Is glycolysis an aerobic or anaerobic process?

Anaerobic

Where does glycolysis occur in both prokaryotes and eukaryotes?

Cytoplasm

In the aerobic respiration of glucose, the inputs are … glucose, … NAD+s, … ATPs, and .. ADPs

1, 2, 2, 4

In the aerobic respiration of glucose, the outputs per 1 glucose are … pyruvates, … NAHDs, … H2Os, and … ATPs

2, 2, 2, 2