Biology 1 Lab

Front 1

Many enzymes are composed of what

Back 1

proteins (polypeptides)

Front 2

Some Ribonucleic acids (RNA) possess an enzyme-like ability to catalyze biochemical reactions, RNA molecules that act as enzymes are known as what?

Back 2

ribozymes

Front 3

A (blank) is a substance that increases the rate of a chemical reaction without being consumed or permanently altered in the process

Back 3

What is a catalyst

Front 4

Do enzymes cause reactions to occur?

Back 4

No, they facilitate reactions that would occur naturally, given enough time.

Front 5

What can you add to Sucrose, the disaccaride composed of glucose molecule covalently bonded to a molecule of fructose will stay bonded for years, but what enzyme can be added to speed up the process to minutes

Back 5

the enzyme sucrase

Front 6

An enzyme speeds the making and breaking of atomic bonds within its substrates (reactant) by

Back 6

temporarily binding it within a pocket or grove on the surface called the active site.

Front 7

How is the 3-dimensional shape of the active site on an enzyme determined

Back 7

by the arrangement of the enzymes constituent amino acids

Front 8

Polypeptides are made up of monomers (single units) known as

Back 8

amino acids

Front 9

What does each amino acid consist of?

Back 9

1. A central carbon (known as the alpha carbon)
2. bound to an amino group (NH2) and one side
3. and a carboxyl group (COOH) on the other side.
4. Also bound to a Hydrogen Atom
5. and a unique side chain (or R-group)

Front 10

What makes the twenty amino acids commonly found in polypeptides different from one another?

Back 10

The side chain connected to the alpha-carbon.

Front 11

What broad categories do the side-chains fall into?

Back 11

polar and non polar

Front 12

What is the three dimensional structure of an enzyme, as in all polypeptides determined by?

Back 12

the unique linear sequence of its amino acids, where is referred to as its rimary structure.

Front 13

In the primary structure, how are the amino acids bonded together

Back 13

The carboxyl gropu of one amino acid is covelantly bound to the amino group of the next amino acid, this is referred to as a "peptide bond"

Front 14

What happens in the polypeptides secondary structure

Back 14

The hydrogen bonding between the hydrogen atoms and the amino group of one amino acid and the oxygen atoms of the carboxyl grop of a nearby amino acid cause the backbone to twist and fold into repeating structural patterns known as alpha-helices and beta-pleated sheets.

Front 15

What kind of bonds occur in the tertiary structure:

Back 15

1. hydrogen bonding between polar side chains
2. Ionic bonds between positively charged and negatively charged polar side chains
3. Covalent bonds between the sulfurs found in the side chains of two cysteine monomers (also known as disulfide bridges)

Front 16

When is there a quarternary structure in a polypeptide

Back 16

If the proteins consist of mora than one polypeptide chain.

Front 17

How does the active site of an enzyme get formed

Back 17

by the folding of the polypeptide placing the non-polar side groups towards the inside and the polar side groups towards the outside. This folding results in the fomation of the active site. Each active site has a specific size and shape.

Front 18

What are the other sites on a an enzyme called that are responsible for binding molecules that regulate enzyme activity

Back 18

"regulatory regions"

Front 19

Does the active site have a charge? Is so, what is it?

Back 19

One end of the pocket can be negatively charged and the other positively charged

Front 20

For a substrate to bind to an enzyme, it must have what?

Back 20

Complementary size, shape and charge.

Front 21

What is it when an enzyme undergoes a conformational change in shape in order to put stress on existing bonds that must be broken in order to convert the substrate into a product

Back 21

"induced fit"

Front 22

At the end of a reaction, is an enzyme the same or different?

Back 22

It remains the same

Front 23

What is a hydrolysis reaction

Back 23

the reaction is split with water.

Front 24

In the lab, how can we determine how much product is formed?

Back 24

The product p-nitrophenol changes color when placed in an alkaline solution, it can be measured colorimetrically using a spectrophotometer. The amount of product formed then can be quantified using a standard curve.

Front 25

Why do we use control samples in the experiment without adding the enzyme?

Back 25

The control is used to see how much product is obtained in the same time frame as the experimental group, to compare to the group that did have the enzyme.

Front 26

What does the alkaline solution do to the sample

Back 26

It stops the reaction, while the change in pH alters the way that p-nitrophenol interacts with light, allowing it to absorb greater amounts of all the wavelengths of the visible spectrum (except for yellow)

Front 27

How can you determine how much product concentration is in each sample?

Back 27

because a stock solution of known product concentration is used to create a series of tubes with lesser but still known concentrations, a process known as serial dilution. A number is given to each given to each degree of concentration when viewed through the spectrophotometer, which will be used to measure the samples.

Front 28

In this lab, what is the standard curve used to measure

Back 28

It's a ruler used to measure solute concentration. A standard curve is the graph in which known concentrations are plotted against their respective measured optical absorbancies, obtained using a spectrophotometer, in theory, a standard curve should be linear.

Front 29

In this lab, what is the x-axis and y-axis used to measure

Back 29

The x-axis measures the solute concentration while the y-axis is used to measure the optical absorbance density.

Front 30

How much does a "mole" of a substance contain?

Back 30

6.02 x 10^23 atoms or molecules, depending on the nature of the substance.