Hettema 1 & 2

Question 1

What are the problems associated with eukaryotes being much larger than prokaryotes?

Answer 1

• sa:v ratio is low

- hard to keep reactant concentration sufficiently high

Question 2

How can the concentrations of reactants be sufficiently high for efficient metabolism?

Answer 2

Compartmentalisation of cellular functions

Question 3

Describe the cytosol.

Answer 3

Aqueous phase of the cytoplasm excluding the organelles, membranes and insoluble structures (cytoskeleton)

Question 4

In which organism is the periplasmic space found and where is it within that organism?

Answer 4

Prokaryotes - in-between the inner and outer membranes surrounding the prokaryote

Question 5

What is the function of the nucleolus?

Answer 5

Granular body consisting of RNA and protein. Site of ribosomal RNA synthesis and ribosome subunit assembly. (not membrane bound)

Question 6

What are the two major endomembrane pathways?

Answer 6

Secretory - ER, Golgi, secretory vesicles

Endocytic - endosomes, phagosomes, lysosomes, autophagosomes

Question 7

What is the function of the RER?

Answer 7

• synthesis of proteins for secretory purposes/incorporation into the plasma membrane

Question 8

Peroxisomes:
O_____ of fatty acids gives off H______ P______.
H_____ P_____ is broken down via the enzyme c______ which is contained within the peroxisome.

Answer 8

Oxidation
Hydrogen Peroxide
catalase

NB: peroxisomes contain a high proportion of proteins therefore can crystallise easily

Question 9

What is the plant cell wall made up of?

Answer 9

• cellulose microfibrils –> rigid structure

- plasmodesmata connect neighbouring cells within plant cell wall

Question 10

Where is the localisation of the mitochondria within a sperm cell?

Answer 10

Single coiled mitochondrion within the midpiece

Question 11

Give the 3 main cytoskeletal elements.

Answer 11

• microtubules
• microfilaments e.g. actin filaments
• intermediate filaments