Biology 1013 Launchpad Ch.4 Quiz

In which examples does a vitamin or mineral function as a cofactor?

- Hydroxylase enzymes require vitamin C during collagen synthesis. - DNA polymerase requires zinc to replicate DNA.

Identify whether the example describes an anabolic or catabolic pathway: - Glycolysis converts one molecule of glucose to two molecules of pyruvate - Photosynthesis generates storage carbohydrates from CO2 and H2O - A lipid molecule is constructed from fatty acid subunits - A protein molecule is broken down into amino acid subunits

Anabolic pathway: Photosynthesis generates storage carbohydrates from CO2 and H2O, A lipid molecule is constructed from fatty acid subunits Catabolic pathway: Glycolysis converts one molecule of glucose to two molecules of pyruvate, A protein molecule is broken down into amino acid subunits

Which of the statements correctly contrasts anabolic and catabolic pathways?

Anabolic pathways are synthesis pathways, whereas catabolic pathways are degradation pathways.

You have identified an enzyme that breaks down a storage form of sugar in plants (starch) into simple sugars. How would this enzyme react with a storage form of sugar (glycogen) in humans?

Because enzymes are specific, the plant enzyme's active site would not bind to glycogen as a substrate.

Which statement regarding cofactors and coenzymes is false?

Cofactors and coenzymes can replace enzymes in cells.

Which part of the graph represents activation energy?

D

Classify each phrase as describing an enzyme, an active site, or a substrate: - A specific enzyme location that binds with the substrate - A biological catalyst - A protein containing an active site - May be a phosphate group - A substance that the enzyme acts upon

Enzyme: A biological catalyst, A protein containing an active site Active site: A specific enzyme location that binds with the substrate Substrate: A substance that the enzyme acts upon, May be a phosphate group

A specialized protein in saliva breaks up starch molecules in food into smaller chains of simple sugars. In this reaction, which molecule is the enzyme, which is the substrate, and which is the product? One of the four answer choices will not be used:

Enzyme: The specialized protein Substrate: The starch molecules Product: The small chains of simple sugars

How do enzymes catalyze reactions?

Enzymes bind with and change the conformation of substrates.

Enzymes take part in nearly all metabolic reactions. What is an enzyme's impact on the activation energy of a chemical reaction? There are two parts. How do enzymes affect the activation energy of a reaction?

Enzymes decrease the activation energy

Which of the statements best describes the overall role of enzymes in metabolism?

Enzymes increase the speed of reactions

Consuming excess amounts of the water-soluble vitamin C can lead to _____.

It is not possible to consume excess amounts of vitamin C.

Scientists generally agree that plants require at least 17 essential nutrients for growth. These nutrients are sometimes broken into two categories: macronutrients and micronutrients. Classify each of the names and statements that describe the essential nutrients as belonging to either the macronutrient category or the micronutrient category: - Require in large amounts - Mainly enzyme cofactors - Phosphorus (P) - Iron (Fe) - Carbon (C) - Required in small amounts - Zinc (Zn) - Main components of organic molecules

Macronutrients: Require in large amounts, Main components of organic molecules, Phosphorus (P), Carbon (C) Micronutrients: Required in small amounts, Mainly enzyme cofactors, Zinc (Zn), Iron (Fe)

Corn lacks the essential amino acids isoleucine and lysine. Beans lack the essential amino acids tryptophan and methionine. Soy contains all the essential amino acids. Based on this information, would you be able to survive on a diet with corn-based proteins alone? Why or why not?

No, because corn does not supply all of the essential amino acids needed in the body

Why must essential amino acids be consumed in our diet?

Our bodies cannot manufacture them.

If the shape of an enzyme's active site were to change, what would happen to the reaction that the enzyme usually conducts?

The conversion of substrate to products would decrease and the enzyme would no longer be able to bind to its substrate efficiently.

Which of these describes a catabolic pathway?

a pathway that breaks down molecules into smaller subunits

Which of these describes an anabolic pathway?

a pathway that generates molecules from smaller subunits

Corn lacks the essential amino acids isoleucine and lysine. Beans lack the essential amino acids tryptophan and methionine. Soy contains all the essential amino acids. Use this information to complete the following statement: Many traditional diets combine corn (e.g., tortillas) with beans to provide _____,

all the essential amino acids

What subunits are proteins broken down into during digestion?

amino acids

What is a vitamin?

an organic compound obtained in the diet that is required for normal metabolism

A(n) _____ reaction creates bonds between substrate units; a(n) _____ reaction breaks down bonds between substrate units.

anabolic; catabolic

What ingredients in RUTF peanut paste specifically help bone growth?

calcium and vitamin D

Enzymes speed up chemical reactions by _____.

decreasing the activation energy

Choose the best definition for activation energy

energy that must be added to start a reaction

Our bodies cannot synthesize vitamin C, but they require it in small amounts. Therefore, vitamin C is a(n) _____.

essential micronutrient

Corn lacks the essential amino acids isoleucine and lysine. Beans lack the essential amino acids tryptophan and methionine. Soy contains all the essential amino acids. Based on this information, is the following statement true or false?

false

To repair a cell membrane, which macronutrient would supply the needed building blocks?

fats

Which of these is a sign of malnutrition?

fluid buildup in the legs and feet

Where (or how) do we obtain essential amino acids?

from protein in our diet

Which describes how cofactors and coenzymes affect the function of enzymes?

increase catalytic function

Activation energy is best defined as the energy that

is required to bring the reactant molecules to a transition state

Which of these foods is a rich source of protein?

lean meat, such as chicken breast

A multivitamin supplement is a(n) _____ supplement.

micronutrient

Which component of the peanut butter ready-to-use-therapeutic food (RUTF) that Dr. Manary uses provides essential amino acids?

milk powder

Certain nutrients that are important for a healthy and balanced diet are considered essential nutrients. Which of the statements describes essential nutrients for the human body?

nutrients that the body cannot synthesize or does not produce in sufficient quantities

The macronutrients include _____.

proteins and fats

A macronutrient is a nutrient _______.

that is required in large amounts

The substrate of an enzyme is _____.

what the enzyme acts on