PROTEIN SECTION LECTURE #2 (Part 2)

Question 1

What is transamination in the context of amino acids?

Answer 1

Transamination is the process by which a nonessential amino acid is synthesized in the body by transferring the amino group from one amino acid to an intermediate that has a carboxylic acid group, forming another non-essential amino acid.

Question 2

Where does transamination typically occur?

Answer 2

Transamination generally occurs in the liver.

Question 3

Can transamination occur for essential amino acids?

Answer 3

No, transamination typically involves the synthesis of nonessential amino acids, as essential amino acids must be obtained from the diet.

Question 4

What is deamination in the context of amino acids?

Answer 4

Deamination is the process of removing an amino group from an amino acid to make other substances.

Question 5

Where does deamination typically take place?

Answer 5

Deamination takes place in the liver.

Question 6

What happens to the rest of the amino acid after deamination?

Answer 6

The rest of the amino acid, which is made mostly of carbon and hydrogen, is recycled into something else or oxidized for energy.

Question 7

What is the fate of the ammonia produced during deamination?

Answer 7

The ammonia produced during deamination turns into toxic ammonia, which is quickly converted to urea and then excreted in urine.

Question 8

What is a condensation reaction in protein synthesis?

Answer 8

A condensation reaction in protein synthesis is a chemical process that takes an OH group from the carboxyl-end of one amino acid and an H atom from the amino end of another amino acid, joining them to form a water molecule and creating a peptide bond between the two amino acids.

Question 9

What is formed as a byproduct of a condensation reaction between two amino acids?

Answer 9

A water molecule is formed as a byproduct of a condensation reaction between two amino acids.

Question 10

What type of bond is created between two amino acids during a condensation reaction?

Answer 10

A peptide bond is created between two amino acids during a condensation reaction.

Question 11

What is a hydrolysis reaction in the context of proteins?

Answer 11

A hydrolysis reaction is the process that breaks a dipeptide bond between two amino acids, using water to split the bond.

Question 12

Peptide bonds:

Answer 12

link amino acids together through condensation reactions

Question 13

Dipeptides:

Answer 13

two amino acids; joined by their backbone, not side chain usually

Question 14

Oligopeptide:

Answer 14

less than 10 AA

Question 15

Polypeptide:

Answer 15

many amino acids (10 or more)

Question 16

Protein:

Answer 16

one or more polypeptide chains folded into a 3D shape

Question 17

Primary structure:

Answer 17

initial sequence of amino acids by peptide bonds

Question 18

Secondary structure:

Answer 18

alpha-helix, beta-pleated (H-bonding)

Question 19

Tertiary structure:

Answer 19

formation of 3D structure of 1 polypeptide chain through hydrophobic/philic interactions and disulfide bridges

Question 20

Quaternary Structure:

Answer 20

3D structure of the interaction of 2 or more polypeptide chains

Question 21

Both _____________ and________________ are polypeptide proteins that have quaternary structures

Answer 21

Hemoglobin

Insulin

Question 22

What does protein denaturation involve?

Answer 22

Protein denaturation involves a change to the 3D structure of a protein, affecting its function by altering its shape rather than its primary structure or amino acid sequence.

Question 23

What are some factors that can cause protein denaturation?

Answer 23

Heat, pH changes, UV radiation, x-rays, and agitation can all cause protein denaturation.

Question 24

Is protein denaturation usually reversible or irreversible?

Answer 24

Protein denaturation is usually a permanent change that renders the protein nonfunctional.

Question 25

Can you give an example of protein denaturation that is commonly observed in cooking?

Answer 25

An example of protein denaturation is the change observed in egg whites when they are cooked or beaten; the clear egg whites become opaque and solid.

Question 26

How can a fever or a change in pH affect proteins in the body?

Answer 26

If you have a fever or if your pH changes, it can have a great effect on the protein functions in the body, potentially leading to denaturation and loss of protein function.

Question 27

Why is it important for proteins to function at an optimal temperature and pH?

Answer 27

Proteins function optimally at a certain temperature and pH because their structure is adapted to these conditions. Deviations can lead to denaturation and loss of function, which can affect the metabolism and overall functioning of the body.

Question 28

How is a mutation different from denaturation?

Answer 28

A mutation is a change in the base sequence of genes, which alters the primary structure of the polypeptide and subsequently affects the secondary, tertiary, and quaternary structures, changing their function.

Denaturation, on the other hand, refers to the alteration of the protein’s structure without changing the primary sequence of amino acids.

Question 29

What causes a mutation?

Answer 29

A mutation occurs when there is an alteration in the base sequence of genes. This genetic change can affect the protein’s primary structure, leading to functional changes

Question 30

Can you describe the process that leads from DNA to a functional protein?

Answer 30

The process from DNA to a functional protein involves transcription, where DNA is transcribed into RNA, followed by translation, where RNA and ribosomes synthesize the protein.

DNA → RNA + ribosomes = protein

Question 31

What is an example of a condition caused by a mutation affecting the shape of a protein?

Answer 31

Sickle cell anemia is a condition caused by a mutation that alters the primary structure of the polypeptide in red blood cells (RBCs), affecting their shape and reducing their oxygen-carrying capacity.