Life at the Cellular 2

Question 1

Define contact dependent cell signalling.

Answer 1

Cells join together and cause an effect in both cells.

Question 2

Define paracrine cell signalling.

Answer 2

Gives an effect to cells in the local area.

Question 3

Define endocrine cell signalling.

Answer 3

Rely on blood to carry a signal around the body to cause an effect.

Question 4

Define synaptic cell signalling.

Answer 4

Specific to neurones and nerve system, chemical reactions.

Question 5

Define cell signalling.

Answer 5

When an external signal binds to a receptor on the cell surface causing a response in the cell.

Question 6

Give 3 features of mitochondria

Answer 6

• inner and outer membrane
• own ribosomes to manufacture proteins
• own circular DNA
• self-replicate

Question 7

Give 3 features of the nucleus

Answer 7

• contains DNA, nucleoprotein and RNA
• DNA (heterochromatin and euchromatin)
• nuclear membrane is a phospholipid bilayer
• contains pores

Question 8

Give 3 features of the endoplasmic reticulum/golgi apparatus

Answer 8

• rough ER has ribosomes attached
• proteins made in ER passed through GA for post translational modifications
• smooth ER breaks down compounds and sometimes does synthesis

Question 9

Give 3 features of lysosomes

Answer 9

• separate enzymes from the rest of the cell
• a type of vesicle
• contain digestive enzymes which are made in the GA
• kept in a vesicle to the cell doesn’t digest itself
• used in autophagy

Question 10

What are the 5 roles of the cytoskeleton?

Answer 10

• support and maintenance of cell shape
• holds organelles in position
• moves organelles
• involved in cytoplasmic streaming
• interacts with extracellular structures to hold cell in place

Question 11

What 3 things is the cytoskeleton made up of?

Answer 11

microfilaments (actin), intermediate filaments (fibrous subunit) and microtubules (tubulin).

Question 12

What are the 2 types of cell surface projections?

Answer 12

Cilia - short and in abundance, move with a stiff power stroke and a flexible recovery stroke

Flagella - long, usually only one or two present and movement is snakelike.

Question 13

Which 10 natural elements are structural parts of organisms?

Answer 13

Hydrogen
Carbon
Nitrogen
Oxygen
Sodium
Phosphorus
Sulfur
Chlorine
Potassium
Calcium

Question 14

Name another element which is very important in the body?

Answer 14

Iron in haemoglobin.

Question 15

Which 4 elements make us 99% of the body and why?

Answer 15

Hydrogen
Oxygen
Nitrogen
Carbon
As they are the 4 lightest atoms that can make 1, 2, 3 and 4 bonds, and the smaller the atom the stronger the bond.

Question 16

What are the two forms of asymmetric molecules?

Answer 16

Laevo (left-handed) and Dextro (right-handed).

Question 17

Why can many biomolecules rotate freely?

Answer 17

They contain c-c bonds.

Question 18

What are the 5 chemical reactions of life?

Answer 18

Redox, making/breaking of c-c bonds, internal rearrangements, group transfer, condensation/hydrolysis.

Question 19

The molecule being oxidised is called the ___ agent and the molecule being reduced is called the ___ agent.

Answer 19

Reducing, oxidising.

Question 20

Define internal rearrangment.

Answer 20

When a molecule changes without the addition or removal of anything. I.e the chemical formula remains the same but the molecule doesn’t.

Question 21

Define a condensation reaction.

Answer 21

Produces water and 1 product.

Question 22

Define a hydrolysis reaction.

Answer 22

Uses water and gives 2 products.

Question 23

What is the normal breakdown of water to chemicals in organisms?

Answer 23

70% water to 30% chemicals.

Question 24

Define proteins.

Answer 24

Polymers of amino acids linked by peptide bonds.

Question 25

Which bases are pyrimidines?

Answer 25

Cytosine, thymine and uracil.

Question 26

Which bases are purines?

Answer 26

Adenine and guanine.

Question 27

Why can RNA form a massive number of shapes?

Answer 27

Due to its ability to be highly folded and it’s single stranded.

Question 28

What reaction are glucose polymers formed by?

Answer 28

Condensation.

Question 29

Define a lipid.

Answer 29

Usually contain one or more long chain fatty acid, can be saturated or unsaturated.

Question 30

Would saturated or unsaturated lipids have a kink in them?

Answer 30

Unsaturated due to no rotation at the C=C bond.

Question 31

Match these words: 
Olive Oil
Mix
Butter
Polyunsaturated
Lard 
Saturated

Answer 31

Olive Oil - polyunsaturated
Butter - mix
Lard - saturated