Cell structure and function

Question 1

What are the 2 major functions of cells?

Answer 1

1. To pass on hereditary information

2. To carry out necessary life functions

Question 2

What are the functions of cytoplasm?

Answer 2

Provides environment for biochemical processes (esp. intermediary metabolism)

Question 3

What features of the plasma membrane determine its mechanical characteristics?

Answer 3

Kinks in unsaturated fatty acids

Cholesterol

Question 4

What is a phospholipid molecule made up of?

Answer 4

Hydrophilic head:
Nitrogenous compound (+)
Phosphate bridge (-)
Glycerol

Hydrophobic tail:
Saturated and unsaturated fatty acid chains

Question 5

What are the 4 types of transport across cell membranes?

Answer 5

Passive diffusion (small, fat-soluble molecules) 
Facilitated diffusion (requires channel or carrier) 
Active transport (requires energy, against conc. gradient) 
Bulk transport (endo- / exocytosis, requires energy)

Question 6

What is the function of rough ER?

Answer 6

Synthesis and secretion of proteins for export from the cell
[Predominantly found in exocrine glands, enzyme producing tissues]

Question 7

What is the function of smooth ER?

Answer 7

Lipid biosynthesis, membrane synthesis and repair

[Predominantly found in steroid hormone secreting cells and hepatocytes]

Question 8

What is the function of cytoplasm?

Answer 8

Houses organelles and site of many metabolic reactions

[Present in all cells]

Question 9

What is the function of mitochondria?

Answer 9

Site of aerobic respiration (ATP production)

[Present predominantly in cells with high energy demands]

Question 10

What is the function of a cell nucleus?

Answer 10

Houses DNA for replication and coding of proteins

[Present in all cells]

Question 11

What is the function of the nucleolus?

Answer 11

Site of ribosomal RNA synthesis and ribosome assembly

[Present in cells that require protein production]

Question 12

What is the function of a cytoskeleton?

Answer 12

Maintains shape, polarity and movement of a cell or part of a cell
[Present in all cells but most abundant in WBCs and muscle cells]

Question 13

What is the function of lysosomes?

Answer 13

Degradation of materials ingested by phagocytosis

[Present predominantly in cells involved in innate immunity e.g. neutrophils]

Question 14

What is the function of Golgi Apparatus?

Answer 14

Protein and lipid glycosylation and synthesis of glycosaminoglycans
[Present predominantly in cells that require protein production for secretion e.g. enzymes]

Question 15

What is the function of perioxisomes?

Answer 15

Enzymatic oxidation predominantly of fatty acids

[Present predominantly in liver cells and Schwann cells]

Question 16

How does staining of nuclei vary?

Answer 16

Tightly coiled DNA (not being expressed) appears dark 
Uncoiled DNA (being used to code for proteins) appears light