Chapter 5 : Homework/Quiz

In feedback inhibition pathways, the end-product of the pathway is usually an inhibitor of the last enzyme in the pathway.

FALSE

What is the major function of fermentation?

It regenerates NAD+ for glycolysis

A molecule that gains an electron from another molecule will experience __________ in its overall electrical charge.

a reduction

Altering the environmental pH can inhibit microorganism growth due to __________.

denaturation of enzymes

NAD+, FAD, and NADP+ are all examples of __________.

electron carriers

Fermentation differs from cellular respiration by __________.

using organic molecules as the final electron acceptor

Chemical reactions that can proceed in either a catabolic or an anabolic direction are known as _______reactions.

......?

The photosynthetic membranes that are similar to mitochondrial membranes in both structure and function are called_____

......?

Oxygenic photosynthesis releases oxygen derived from_______

.....?

Which of the following is NOT an example of metabolic regulation by a cell?

Cells close all channels in the membrane if no energy sources are needed

All of the following processes are ways that a cell can use a proton gradient EXCEPT __________

Electron transport

Fermentation is more energy efficient than aerobic glucose metabolism.

FALSE - Fermentation produces products that have industrial applications, but cells require more glucose to grow when relying on fermentation

The carrier molecules in electron transport chains are all integral membrane proteins

FALSE - Ubiquinones are electron transport molecules that are lipid-soluble, nonprotein carriers

Fermentation results in the production of carbon dioxide and water from pyruvic acid

FALSE - in fermentation, pyruvic acid is generally converted into organic waste products such as alcohol and lactic acid

ATP is made by substrate-level phosphorylation only during glycolysis

FALSE- A small amount of ATP is also made by substrate-level phosphorylation during the Krebs cycle.

Folic acid is a precursor molecule necessary for the synthesis of which of the following?

Nucleotides

_______ phosphorylation is the process in which photosystem I works with photosystem II, and electrons are used to reduce NADP+ to NADPH.

Oxidative

Carbon dioxide is produced only as a by-product of acetyl-CoA synthesis and the Krebs cycle during cellular respiration

TRUE - Carbon dioxide is produced whenever decarboxylation occurs in cellular respiration.

Acidic pH breaks the hydrogen bonds that give enzymes their characteristic shapes, thereby denaturing them

TRUE - Protons interfere with low-energy hydrogen bonds.

A coenzyme __________.

can be derived from a vitamin

Sulfanilamide is a drug that interferes with bacterial enzymes in which of the following ways?

competitive inhibition

Feedback inhibition __________.

is a mechanism for controlling the actions of enzymes

The activation energy of a chemical reaction __________.

is lower in the presence of an enzyme

Which of the following does NOT affect the activity of an enzyme?

oxygen concentration

All of the following are associated with the process of glycolysis EXCEPT __________.

production of NADPH

Biological oxidations often involve which of the following?

the loss of a hydrogen atom

Which of following are INCORRECTLY paired?

transition step: two molecules of acetyl-CoA per one molecule of pyruvic acid