Proteins

Question 1

Globular Protein Features

Answer 1

Rounded

Functional role

Soluble in water

Irregular amino acid sequence

Question 2

Storage of Carbohydrates, Fats and Proteins

Answer 2

Carbohydrates and Fats: Can be stored

Proteins: Can’t be stored

Question 3

Water Soluble Proteins

Answer 3

Non-polar amino acids tend to move towards the center of the molecule which maximizes hydrophobic interactions between amino acids to stabilize the molecule

Polar amino acids tend to move towards the protein surface which maximizes hydrogen bonding

Question 4

Fibrous Protein Features

Answer 4

Long and narrow

Structural role

Insoluble in water

Repetitive amino acid sequence

Question 5

Explain Secondary Protein Structure

Answer 5

The polypeptide chains are coiled or pleated into different shapes:

Alpha Helix: A helical 3D shape

Beta-pleated Sheet: Parallel sections of polypeptide chains that run in opposite directions

Question 6

Condensation Reaction

Answer 6

The formation of two amino acids forming a dipeptide, but removes water to form peptide bond.

Question 7

The 7 Proteins and their Functions

Answer 7

Hemoglobin: Transport

Actin and Myosin: Muscle contraction

Rubisco: Enzyme

Immunoglobulins: Immunity

Rhodopsin: Receptor

Insulin: Hormonal

Collagen: Structural

Question 8

Difference with a Conjugated and Non-conjugated Protein

Answer 8

Conjugated: Combined an inorganic component called a prosthetic group

Non-conjugated: Made of polypeptide chain that is not associated with other chemical groups

Question 9

Simplest Unit of Carbohydrates, Fats and Proteins

Answer 9

Carbohydrates: Monosaccharides

Fats: Fatty Acids and Triglycerides

Proteins: Amino Acids

Question 10

Protein Elements

Answer 10

CHONS

Carbon, Hydrogen, Oxygen, Nitrogen, (Sometimes) Sulfur

Question 11

Explain Primary Protein Structure

Answer 11

A sequence of amino acids in a polypeptide molecule.

It is specific, predictable, and repeatable.

Its precision determines the 3D structure and function

Question 12

Insulin and Function

Answer 12

Made of two polypeptide chains linked by disulfide bonds which is quaternary

Its shape allows it to bind to insulin receptors to regulate glucose uptake

Question 13

pH in Denaturation

Answer 13

Changing the pH affects the ionic bond between opposite charges of non-adjacent amino acids, which will alter protein shape

Changes in pH also affect the strength of the hydrogen bond

Question 14

Origin of Carbohydrates, Fats and Proteins

Answer 14

All of them are plant

Question 15

Explain Quaternary Protein Structure

Answer 15

Two or more polypeptide chains join to form a protein

Question 16

How many Sequences relating to Amino Acids

Answer 16

For every polypeptide with n amino acids, there are 20^n possible sequences

Question 17

Solubility of Carbohydrates, Fats and Proteins

Answer 17

Carbohydrates: Only sugars are soluble

Fats: Low solubility is soluble

Proteins: Some are soluble

Question 18

Denaturation

Answer 18

A permanent irreversible change in the 3D structure of a protein that results in the loss of their natural function

Question 19

Explain Tertiary Protein Structure

Answer 19

3D because of protein folding, and is stabilized by intramolecular bonds that form between amino acids’ R groups.

Amino acids include:

Hydrogen Bonds
Disulfide Bonds
Ionic Bonds
Hydrophobic Interactions

Question 20

Amino Acid Basic Structure

Answer 20

Amine Group

Carboxyl Group

Carbon in the middle which bonds
with Hydrogen Atom

R Group which is specific to each amino acid (20 R Groups correspond to 20 Amino Acids)

Question 21

Difference with Essential and Non-Essential Amino Acids

Answer 21

Essential: Can not be synthesized in the body and must be included in diet

Non-Essential: Can be synthesized in the body from other amino acids

Question 22

The 4 Protein Structures

Answer 22

Primary

Secondary

Tertiary

Quaternary

Question 23

Bond of Carbohydrates, Fats and Proteins

Answer 23

Carbohydrates: Glycosidic Bond

Fats: Ester Bond

Proteins: Peptide Bond

Question 24

Membrane Bound Proteins

Answer 24

Non-polar amino acids tend to connect themselves in the membrane away from water which creates a stable environment within the membrane

Polar amino acids are found on the aqueous environment inside and outside the cell which facilities the stability of the protein

Question 25

Elements of Carbohydrates, Fats and Proteins

Answer 25

Carbohydrates and Fats: CHO

Proteins: CHONS

Question 26

Hydrolysis Reaction

Answer 26

Hydrolysis breaks dipeptide down into 2 amino acids, but uses water to split

Question 27

Temperature in Denaturation

Answer 27

High temperature disrupts the hydrogen bonds that hold the protein together, thus when the bonds break down the protein unfolds and loses its function

Question 28

Structural and Function

Answer 28

A fibrous protein made from 3 polypeptide chains held closely by covalent and hydrogen bonds to form a triple helix

Forms the main structure in tissues such as skin, blood vessels and ligaments

Quaternary

Question 29

Rubisco and Function

Answer 29

Has a rounded shape that is tertiary, which provides three dimensional active site where a substrate can bind

The prosthetic group can be a metal ion

Question 30

Hemoglobin and Function

Answer 30

Transport protein

Made of 4 polypeptide chains and has 4 heme prosthetic groups

Each heme group binds to oxygen and transports it with the red blood cell