Session 1-Basic Cell Structure

Question 1

What is a nucleosome?

Answer 1

Structural unit of eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones

Question 2

What is heterochromatin?

Answer 2

Chromosome material that stains most deeply when the cell isn’t dividing
Genetically inactive
Tightly coiled

Question 3

What is euchromatin?

Answer 3

Chromosome material that stains most deeply during mitosis.
Prevalent in cells that are active in transcription of many genes.
Loosely coiled

Question 4

What is the glycocalyx made up of?

Answer 4

Oligosaccaride and polysaccharide side chains

Question 5

What are the functions of the plasmalemma? (6)

Answer 5

Selective permeability 
Transport materials along cell surface
Endo and exocytosis
Intercellular adhesion
Intercellular recognition 
Signal transduction

Question 6

What is the function of the Golgi apparatus?

Answer 6

Modify, sort, concentrate and package proteins synthesised on the RER

Question 7

What are lysosomes?

Answer 7

Generated by the Golgi apparatus and contain many hydrolytic enzymes. They fuse with material requiring digestion.

Question 8

What do peroxisomes do?

Answer 8

Oxidise number of molecules like alcohol, phenols, formic acid and formaldehyde

Question 9

What is the function of the mitochondria?

Answer 9

To generate ATP by oxidative phosphorylation

Question 10

What are the functions of the endoplasmic reticulum?

Answer 10

Lipid and steroid synthesis

Membrane synthesis

Question 11

What are the functions of the nucleus?

Answer 11

RNA synthesis
DNA synthesis and repair
RNA processing and ribosome assembly

Question 12

What is the function of ribosomes?

Answer 12

Protein synthesis

Question 13

What are the functions of cytoplasm?

Answer 13

Fatty acid synthesis

Metabolism of carbs, AA and nucleotides

Question 14

How can differences in bacterial and mammalian cell structure and function be exploited in medicine?

Answer 14

Antibiotics (eg penicillin) prevents the final cross-linking step of producing peptidoglycan which makes the cell wall of the bacteria. This means that the cell is now fragile and bursts, killing the bacterium.

Question 15

Define amphipathic

Answer 15

Molecule that has both hydrophobic and hydrophilic parts

Question 16

How can rapid breathing (hyperventilation) cause an increase in blood pH?

Answer 16

When the body receives more O2 than it needs, the result is known as respiratory alkalosis which causes an increase in blood pH.

Question 17

What effect would pulmonary obstruction have on blood pH?

Answer 17

Decrease pH - inefficient gas exchange so excess CO2 in blood, making acidic carbonic acid (respiratory acidosis)

Question 18

What are microtubules?

Answer 18

Long hollow cylinders made of the protein tubulin, found at sites where structures are moved (ie nerve fibres, mitotic spindle, cilia and flagella)

Question 19

What causes the blistering of skin?

Answer 19

Mutant keratin gene

Question 20

What are intermediate filaments?

Answer 20

These are common in epithelial cells and form a tough supporting mesh work in the cytoplasm. They can also be found beneath the inner nuclear membrane forming the nuclear lamina

Question 21

What is the limit of resolution?

Answer 21

Minimum distance at which two objects can be distinguished

Question 22

Where can the SER be found?

Answer 22

Liver, mammary gland (lipid biosynthesis), ovary, testis and adrenal gland (steroidogenesis)

Question 23

What does the trans face of the Golgi body do?

Answer 23

Secrete substances

Question 24

What does the cis face of the Golgi body do?

Answer 24

Form substances

Question 25

What is the medical name for blistering of skin?

Answer 25

Epidermolysis bullosa