Proteins

Question 1

What elements do proteins contain

Answer 1

Carbon, hydrogen, oxygen and nitrogen

Question 2

What other small amounts of elements can be found in proteins

Answer 2

Sulfur and phosphorous

Question 3

Is there a ratio for elements in a protein

Answer 3

There is no ratio

Question 4

Are proteins big or small, simple or complex?

Answer 4

They are very large and complex

Question 5

What are proteins composed of

Answer 5

Amino acids

Question 6

Hw many common amino acids are found I proteins

Answer 6

20 common amino acids

Question 7

What is the bond between amino acids called?

Answer 7

The bond between amino acids is called a peptide bond

Question 8

What is a peptide made of?

Answer 8

A peptide is made of a small number of amino acids (less than 20)

Question 9

Does a polypeptide contain more or less than 20 amino acids

Answer 9

A polypeptide has more than 20 amino acids

Question 10

What is a protein?

Answer 10

A protein is a long polypeptide (at least 200 amino acids)

Question 11

How can there be such a huge range of proteins?

Answer 11

Amino acids can be combined in different sequences

Question 12

The way in which proteins work does not depend on what?

What else does it depend on?

Answer 12

Does not depend on the amin acid sequence alone.

The manner in whixh proteins are folded to take up three dimensional shapes is equally important

Question 13

Exlplain fibrous proteins

Give an example

Answer 13

Fibrous proteins show little or no folding. They form long fibres and are strong and tough
E.g. keratin in hair, nails and feathers

Question 14

Explain globular proteins

Give exampls

Answer 14

Globular proteins show lots of folding. They form rounded shapes 
Egg white (albumen) and enzymes

Question 15

List sources of proteins

Answer 15

Meat, fish, eggs, milk, nuts, peas and beans

Question 16

Where are amino acids stored?

Answer 16

They are not stored in the body.

Question 17

Where are surplus amino acids taken?

Answer 17

They re taken ro the liver and converted to urea, a toxic waste product. This process is called deamintion.
Urea is carried by the blood from the liver to the kidneys.
In the kidneys, urea becomes part of urine and is excreted.

Question 18

Explain what happens to urea in the body

Answer 18

Urea is carried by the blood from the liver to the kidneys.

In the kidneys, urea becomes part of urine and is excreted.

Question 19

What is the structural role of proteins

Answer 19

Fibrous proteins such as keratin is found in skin and hair.

Myosin (motor protein) is found in muscle

Question 20

What is the metabolic role of proteins

Answer 20

They are sued as enzymes to control reactions.
They form antibodies to fight infection.
Some hormones are protein-based and are used to regulate body reactions.