Bioch

Question 1

An amino acid is an organic compound containing both an amino group (-NH2) and a carboxyl group (-COOH) attached to the same carbon atom, called the α-carbon.

Answer 1

Amino Acids

Question 2

There are 20 standard α-amino acids found in proteins.

Answer 2

Standard Amino Acids

Question 3

4 categories of amino acids

Answer 3

Nonpolar, Polar Neutral, Polar Acidic, Polar Basic

Question 4

Hydrophobic side chains. Nonpolar amino acids include alanine, valine, leucine, proline, methionine, tryptophan, glycine, isoleucine, and phenylalanine.

Answer 4

Nonpolar

Question 5

Polar side chains that do not carry a charge

Answer 5

Polar Neutral

Question 6

Contain two amino groups and carry a positive charge at physiological pH. These are arginine (Arg), lysine (Lys), and histidine (His)

Answer 6

Polar Basic

Question 7

Amino acids that must be obtained from the diet because the body cannot synthesize them in adequate amounts.

Answer 7

Essential Amino Acids

Question 8

Contain two carboxyl groups and carry a negative charge at physiological pH. These are aspartic acid or aspartate (Asp) and glutamic acid or glutamate (Glu).

Answer 8

Polar Acidic

Question 9

What are the essential amino acids

Answer 9

Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine.

Question 10

Contain all essential amino acids (e.g., animal proteins, soy).

Answer 10

Complete Amino Acids

Question 11

Lack one or more essential amino acids (e.g., most plant proteins).

Answer 11

incomplete proteins

Question 12

The essential amino acid missing or in low quantities in an incomplete protein.

Answer 12

Limiting Amino Acids

Question 13

Examples of limiting amino acids

Answer 13

Lysine (wheat), methionine (beans), tryptophan (corn).

Question 14

Combining incomplete proteins (e.g., rice and beans) to provide all essential amino acids.

Answer 14

Complementary Proteins

Question 15

at high pc basic

Answer 15

amino acids lose a proton and carry a negative charge.

Question 15

At low ph (acidic)

Answer 15

amino acids gain a proton and carry a positive charge

Question 15

is a molecule with both positive and negative charges but no net charge

Answer 15

Zwitterion

Question 16

the amino acid has no net charge and does not migrate in an electric field.

Answer 16

isoelectric point

Question 17

-COOH group is placed at the top, -R group at the bottom.
-NH2 group is horizontal; left for the L-isomer, right for the D-isomer.

Answer 17

Fischer Projection

Question 18

Unique because its side chain forms a ring with the amino group, making it rigid

Answer 18

Proline

Question 19

Contains a sulfur atom and forms disulfide bonds, which stabilize protein structure.

Answer 19

Cysteine

Question 20

Aromatic Amino Acids

Answer 20

Phenylalanine, tryptophan, and tyrosine have aromatic side chains.

Question 21

refers to the specific sequence of amino acids in a protein.

Answer 21

primary protein structure

Question 22

Amino acids in the primary structure are linked by peptide bonds.

Answer 22

Bonding

Question 23

Determined the primary structure of insulin.

Answer 23

Frederick Sanger (1953):

Question 24

Refers to the spatial arrangement of the protein’s backbone.

Answer 24

Secondary Protein Structure

Question 24

Consists of 51 amino acids in a specific sequence.

Answer 24

Insulin Structure

Question 25

Two types of secondary protein structure

Answer 25

Alpha Helix, Beta pleated sheet

Question 26

Coiled spring stabilized by hydrogen bonds.

Shape: Helical, resembling a coiled spring.
Stabilization: Hydrogen bonds between the carbonyl oxygen and the hydrogen of the amino group in the backbone. are common in fibrous and globular proteins.

Answer 26

Alpha Helix

Question 27

Chains align side by side, stabilized by hydrogen bonds (can be parallel or antiparallel).

Extended sheet-like structure.
Chain Alignment: Can be parallel (chains run in the same direction) or antiparallel (chains run in opposite directions).
Stabilization: Hydrogen bonds between adjacent chains. Beta sheets are crucial for structural stability in proteins like silk fibroin.

Answer 27

Beta Pleated Sheet

Question 28

Function: Proteins acting as biochemical catalysts are enzymes.
Importance: Enzymes accelerate biochemical reactions in cells, which are essential for various metabolic processes.
Example: Enzymes involved in digestion and cellular metabolism, such as amylase or lipase.

Answer 28

catalytic protein