Enzymes and Macromolecules

Practice fill-in-the-blank flashcards covering enzyme mechanics, reaction kinetics, and macromolecular structures.

Enzymes work by lowering the __________ needed for a reaction to occur.

activation energy

In the lock-and-key model shown below, the enzyme represents the lock and the __________ represents the key.

substrate

The specific region of an enzyme where the substrate binds and the chemical reaction takes place is known as the __________ site.

active

The term __________ refers to the pH or temperature at which an enzyme functions most effectively and achieves its fastest reaction rate.

optimal

When an enzyme undergoes an alteration in shape that causes it to lose its ability to function properly, it is said to __________.

denature

During protein thermal irreversible denaturation, native albumen changes from being water-soluble to __________.

insoluble

According to the optimal temperature graph shown below, the reaction rate reaches its peak at approximately __________.

$$40\,^{\circ}\mathrm{C}$$

The provided experimental graph measures the effect of pH on the reaction rate of the enzyme __________.

peroxidase

Increasing enzyme concentration will increase the reaction rate only if there is sufficient __________ available.

substrate

When all active sites of available enzymes are occupied by substrate molecules, the enzymes are said to be __________.

saturated

If an enzyme produces $10$ molecules of product in $1\,\mathrm{second}$, its reaction rate is faster than an enzyme that produces only __________ molecules in $1\,\mathrm{second}$.

$$2$$

As illustrated in the reaction progress diagram, the presence of an enzyme lowers the __________.

activation energy

A competitive inhibitor has a shape similar to the substrate and directly blocks the enzyme's __________.

active site

A noncompetitive inhibitor binds to an enzyme somewhere other than the active site, and adding more substrate __________ overcome the inhibition.

does not

In the diagram below, molecule A represents competitive inhibition because the inhibitor directly enters the __________ site.

active

Carbon is a nonmetal with an atomic number of $6$ and an atomic mass of __________.

$$12.01$$

While diamond is an isotope form of carbon that forms a crystal structure, __________ is identified as the softest substance.

graphite

A subunit that serves as the fundamental building block of a polymer is called a __________.

monomer

The term polymer comes from the Greek word meaning __________.

many

Monosaccharides are simple carbohydrates that contain between __________ carbon atoms.

$$3-7$$

Glucose, galactose, and fructose all share the identical molecular formula of __________.

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$

In the carbonyl structural features shown below, a carbonyl carbon bonded to two separate carbon atoms forms a(n) __________.

ketone

Based on the structure of their carbonyl group, glucose and galactose are classified as aldehydes, while fructose is classified as a(n) __________.

ketone

The disaccharide sucrose is composed of the two monosaccharides glucose and __________.

fructose

The disaccharide lactose is composed of glucose and __________.

galactose

The disaccharide maltose is composed of two molecules of __________.

glucose

Plants use the polysaccharide __________ to store sugar molecules.

starch

In animals, energy is stored in the muscles and liver in the form of the polysaccharide __________.

glycogen

The polysaccharide that provides structural rigidity to plant cell walls is __________.

cellulose

Fatty acid chains whose carbon atoms are fully loaded with hydrogen atoms and lack double bonds are classified as __________ fats.

saturated

Unsaturated fats contain double bonds between carbon atoms and exist in a __________ state at room temperature.

liquid

As shown in the diagram of the cell membrane, the membrane framework consists of a bilayer of __________ embedded with proteins.

phospholipids

In the phospholipid structure shown, the hydrophilic head consists of a phosphate group attached to __________.

glycerol

Low-density lipoprotein (LDL) is commonly termed 'bad' cholesterol because it contains more cholesterol and less __________.

proteins

There are $22$ different amino acids that build proteins, of which exactly __________ are classified as essential.

$$9$$

In the amino acid structure shown below, the specific identity and property of the amino acid is determined by the __________.

R group

A covalent bond formed between the acid group of one amino acid and the amino group of another by removing water is called a __________ bond.

peptide

The secondary structure of a protein includes folding into a beta sheet or coiling into a(n) __________.

alpha helix

A protein that consists of more than one amino acid chain exhibits a __________ structure.

quaternary

As shown in the nucleotide diagram below, each nucleotide monomer is composed of a phosphate group, a 5-carbon sugar, and a __________.

nitrogenous base

In RNA base pairing, adenine pairs with __________, whereas in DNA it pairs with thymine.

uracil