B1.2 Proteins

Question 1

How does pH and temperature affect protein structure?

Answer 1

Each protein has an optimum pH and temperature it works best at
Outside of this range, proteins denature (change shape) and lose their function

Question 2

Components of an amino acid

Answer 2

Amine group (-NH₂), carboxyl group (-COOH), R group (what differs between different amino acids)
All amino acids follow this structure

Question 3

How do chains of amino acids form?

Answer 3

A condensation reaction occurs between two or more amino acids, releasing water and forming a dipeptide or longer chain of amino acids
The bond between two amino acids is called a peptide bond
You need to be able to draw this reaction (as it appears in the image)

Question 4

How many amino acids are there?

Answer 4

20 amino acids

Question 5

How many possible proteins are there?

Answer 5

Millions of proteins are possible because amino acids can be arranged in any order and in any amount
According to probability, there are an infinite number of possible peptide chains

Question 6

Examples of proteins that humans create

Answer 6

Insulin, collagen, keratin, rhodopsin

Question 7

Non-essential amino acid

Answer 7

An amino acid that can be synthesized by the body from other amino acids

Question 8

Essential amino acid

Answer 8

An amino acid that must be obtained from food because the body cannot synthesize it

Question 9

How many essential amino acids are there?

Answer 9

9 essential amino acids (don’t need to know what they are, just need to know that there are nine of them)

Question 10

Dietary considerations for vegans

Answer 10

Vegans need to carefully monitor their diet to ensure they are consuming all 9 essential amino acids, although this can be done pretty easily