Introduction

Question 1

Central dogma theory

Answer 1

DNA (replication) –> RNA (transcription) –> proteins (translation)

Question 2

Reverse transcription

Answer 2

Going from RNA to DNA

Uses reverse transcriptase, an enzyme that generates complimentary DNA (cDNA) from the RNA template. This violates the central dogma theory.

Question 3

Non-coded RNA

Answer 3

This skips the translation into protein, meaning it deviates the central dogma theory.

Can directly perform functions in the cell (e.g., tRNA, rRNA)

Question 4

Functions of proteins

Answer 4

• can act as a biological catalyst
• function in transport
• gives structure
• immunity
• mobility
• communication

Question 5

What are proteins made up of?

Answer 5

Amino acids (20 different ones). The sequence of AA’s determine the 3D structure of the protein.

Question 6

Structure of amino acids

Answer 6

The main 20 amino acids are alpha amino acids. They contain a central alpha carbon, an amino group (NH3) and a carboxylic acid group (COO).

The additional side chain (R-group) are what differentiates the amino acids.

Question 7

Chiral carbon

Answer 7

This means that it has 4 groups attached. 19/20 of the amino acids are chiral, with the exception being glycine because it has another H as the R-group.

Question 8

(S) vs. (R) configuration

Answer 8

(S) configuration has the groups pointing in a counterclockwise direction. (highest priority –> lowest priority)

(R) configuration has groups pointing in a clockwise direction

Question 9

Zwitterion

Answer 9

This is a dipolar molecule, with a protonated amino group and a deprotonated carboxylic acid group.

The zwitterion point is known as the isoelectric point

Question 10

What happens to a zwitterion if we decrease the pH?

Answer 10

At a low pH, more H+ ions are added. The carboxylic acid is protonated, giving it a neutral charge. The overall amino acid has a positive charge

Question 11

What happens to a zwitterion if we increase the pH?

Answer 11

At a high pH, fewer H+ ions are added. The amino group becomes deprotonated, giving it a neutral charge. The overall amino acid has a negative charge.

Question 12

Peptide bonds in amino acids

Answer 12

These link the AAs together to form a protein. They are formed through a dehydrolysis reaction, giving off a water molecule in the process.