Lecture 3: Molecular Composition of the Cell

Question 1

What are the 4 types of Carbohydrates?

Answer 1

Monosaccharides, Disaccharides, Oligosaccharides and Polysaccharides.

Question 2

How many carbons do hexose monosaccharides have?

Answer 2

6

Question 3

How many carbons do pentose monosaccharides have?

Answer 3

5

Question 4

What are the 3 main functions of carbohydrates?

Answer 4

1. Recognition (on the cell surface, cell to cell)
2. Energy
3. Structure

Question 5

Which carbohydrates can be used as energy?

Answer 5

Only starch and glycogen - NOT CELLULOSE.

Question 6

Are lipids polymers?

Answer 6

No!

Question 7

Are lipids heterogenous or homogenous?

Answer 7

Heterogenous

Question 8

Lipids are hydrophobic. True or False?

Answer 8

True

Question 9

What are the three main functions of lipids?

Answer 9

Structure, regulation and energy.

Question 10

What are two examples of nucleic acids?

Answer 10

DNA and RNA

Question 11

What is the function of nucleic acids?

Answer 11

They are information molecules.

Question 12

What is a nucleic acid made up of?

Answer 12

Nucleotides

Question 13

What are nucleotides made up of?

Answer 13

A phosphate, a sugar and a base.

Question 14

What types of nucleic bases exist?

Answer 14

Purines and Pyrimidines.

Question 15

What are proteins?

Answer 15

They are polymers of amino acids.

Question 16

How many different proteins exist, and what makes them different?

Answer 16

20. They each differ by their ‘R’ group.

Question 17

List three building blocks and the corresponding macromolecules they give rise to.

Answer 17

Amino acids ➡ Proteins
Simple carbohydrates ➡ Complex carbohydrates
Nucleobases ➡ DNA or RNA

Question 18

What is a macromolecule?

Answer 18

‘Biopolymers’

Very large molecules created by polymerisation of building blocks.

Question 19

Give 4 examples of macromolecules.

Answer 19

proteins
DNA (nucleic acid)
RNA (nucleic acid)
complex carbohydrates
lipids

Question 20

One of the 4 macromolecules is different from the other 3. Which one and in what
way is it different?

Answer 20

Lipids. Lipids are not polymers.

Question 21

Give an example of a common building block (monomer) of carbohydrates.

Answer 21

Monosaccharides

Question 22

What type of structural carbohydrate is found in plants?

Answer 22

Cellulose

Question 23

Which lipid(s) can be found in cell membranes?

Answer 23

Cholesterol and phospholipids.

Question 24

Name two regulatory lipids derived from cholesterol.

Answer 24

Testosterone and Estradiol ( an estrogen).

Question 25

What is the function of proteins in our cells?

Answer 25

Proteins perform a variety of biological functions

Question 26

Which bases can be found in DNA and RNA nucleotides respectively?

Answer 26

DNA: C, G, A & T
RNA: C, G, A & U

Question 27

What is the difference between a DNA and an RNA nucleotide (assuming the
base component is the same)?

Answer 27

DNA has a deoxyribose sugar, whereas RNA has a ribose sugar.

Question 28

How do DNA and RNA polymers differ structurally?

Answer 28

DNA is double stranded, RNA is single stranded.