BIOL105 Midterm 2

Substrate

(a)

without

(a)

Induced Fit

(b)

with

(b)

Products

(c)

Active Site

(d)

Enzyme

(e)

specialized protein

A specialized protein in saliva breaks up starch molecules in food into smaller chains of simple sugars. What is the enzyme?

smaller chains of simple sugars

A specialized protein in saliva breaks up starch molecules in food into smaller chains of simple sugars. What is the product?

starch molecules

A specialized protein in saliva breaks up starch molecules in food into smaller chains of simple sugars. What is the substrate?

activation; increase; cellular reaction

An enzyme catalyzes a reaction in a way that results in a lower _____ energy to _____ the rate of a _____.

fits the shape; complements the charge

An enzyme recognizes its substrate by a binding site that _____ and _____ of the substrate.

c->b->e->a->d

Arrange the steps that describe the flow of energy from sunlight to cellular work: a) Sugars are broken down by the plant. b) Chloroplasts of primary producers absorb light energy. c) Light energy is given off by the sun. d) Breakdown of sugars releases chemical energy that can power cellular work. e) Light energy, water, and CO2 are used to generate sugars through photosynthesis.

Potential; Chemical

Energy stored in chemical bonds is a form of _____ energy. ATP and carbohydrates are reservoirs of _____ energy.

lower

Enzymes _____ the activation energy of a reaction.

Kinetic

Examples of _____ energy: 1) Diffusion of molecules across the plasma membrane. 2) Muscle contraction.

Potential

Examples of _____ energy: 1) Glucose stored in liver cells. 2) ATP

Catabolic

Examples of a(n) _____ pathway: 1) Glycolysis converts one molecule of glucose to two molecules of pyruvate. 2) A lipid molecule is broken down into fatty acid subunits.

Anabolic

Examples of a(n) _____ pathway: 1) Photosynthesis generates storage carbohydrates from C02 and H20. 2) A nucleic acid molecule is constructed from nucleotide subunits.

Transformation

Examples of energy _____: 1) An oven uses electrical energy to generate heat to bake a cake. 2) An individual uses energy obtained from eating a sandwich to run a marathon. 3) A plant uses light energy to construct sugars in photosynthesis.

metabolic

Feedback inhibition is important for the regulation of many _____ pathways.

produced; photosynthesis; broken down; cellular respiration

Glucose is _____ during _____ to hold energy gathered from light, whereas glucose is _____ during _____ to release stored cellular energy.

Repel; negatively

In ATP, the phosphate groups _____ each other due to multiple _____ charged atoms.

binds; preventing; synthesis

Penicillin is an enzyme-inhibiting antibiotic that kills bacteria by suppressing the synthesis of bacterial cell walls. The bacterial cell wall is made of cross-linked peptidoglycan, which is synthesized from peptidoglycan monomers by transpeptidase enzymes. How does penicillin suppress the synthesis of bacterial cell walls? Penicillin _____ to the transpeptidase enzymes, _____ the _____ of cross-linked peptidoglycan.

Competitive Inhibition

The following are examples of _____: 1) Ethanol outcompetes ethylene glycol for binding to the enzyme alcohol dehydrogenase. 2) Ibuprofen binds tightly to the active site of COX enzymes instead of the natural substrate.

Allosteric Inhibition

The following are examples of _____: 1) Isoleucine inhibits an enzyme by binding to a regulatory domain that is separate from its catalytic domain. 2) Adenosine triphosphate (ATP) prevents the synthesis of additional ATP by binding to a protein domain that does not include the active site.

Feedback Inhibition

The following are examples of _____: 1) The beginning of glycolysis is inhibited by high levels of ATP in the cell. 2) The production of tryptophan is halted by presence of excess tryptophan.

Chemical Potential Energy

The following are examples of the _____ in ATP: 1) ATP hydrolysis induces a conformational change in a protein that moves ions across a membrane. 2) A phosphate group is transferred from ATM to glucose during glycolysis.

First Law of Thermodynamics; transform; convert

The following are examples of the _____: 1) Plants _____ light energy into chemical energy by photosynthesis. 2) Animals eat to obtain chemical energy that they _____ into kinetic energy.

Second Law of Thermodynamics; energy

The following statement describes the _____: Biological systems require an input of _____ to remain highly ordered.

Entropy

The second law of thermodynamics states that the _____ in a system constantly increases.

Exergonic

These examples are _____: 1) Breakdown glucose in cellular respiration. 2) A boulder falling off of a cliff. 3) Metabolizing a protein into amino acids.

Endergonic

These examples are _____: 1) Generating carbohydrates in photosynthesis. 2) Pedaling a bike up a steep hill. 3) Constructing DNA from nucleotides.

Induced Fit

When an enzyme binds to a substrate with _____, the shape of the enzyme's active site changes to more tightly bind to the substrate.

Tightly

When an enzyme binds to a substrate with induced fit, the shape of the enzyme's active site changes to more _____ bind to the substrate.