1. Eukaryotic Cell

Question 1

Organelles present in a eukaryotic cell

Answer 1

1. Nucleus
2. Cytosol
3. Cytoskeleton
4. Adhesion proteins
5. Plasma membrane
6. RER
7. SER
8. Golgi Apparatus
9. Mitochondria
10. Ribosomes (free/RER)
11. Lysosomes | Peroxisomes | Endosomes | Vesicles

Question 2

Function of the nucleus

Answer 2

1. Contains DNA
2. Site of transcription

Question 3

Function of the cytosol

Answer 3

1. Contains organelles
2. Site of translation

Question 4

Function of the cytoskeleton

Answer 4

1. Provides structure to the cell.
2. Allows the cell to migrate by pushing out into the plasma membrane.
3. Allows movement of the molecules within the cell.

Question 5

Function of adhesion proteins

Answer 5

1. Attaches the cytoskeleton to the plasma membrane

Question 6

Functions of the RER

Answer 6

1. Synthesis, post-translational modification and transport of proteins
2. Assembly and folding of proteins (disulphide bond formation)
3. Error checking & quality control: Biosynthetic arrest of misfolded proteins

Question 7

Functions of the SER

Answer 7

1. Synthesis of lipids.

Question 8

Functions of the Golgi apparatus

Answer 8

1. Sorting and modification of proteins.
2. Packaging and transport of proteins. Cis = entry | Trans = exit

Question 9

Functions of the mitochondria

Answer 9

1. Site of oxidative phosphorylation
2. ATP synthesis

Question 10

Function of lysosomes

Answer 10

1. Degradation of macromolecules.

Question 11

Function of peroxisome

Answer 11

1. Uses molecular oxygen to oxidise organic molecules.

Question 12

Function of endosome

Answer 12

1. Processes proteins that have been internalised (by endocytosis)

Question 13

Function of vesicles

Answer 13

1. Transport of substances in the cell

Question 14

Functions of the plasma membrane

Answer 14

1. Physical isolation - encloses the cell AND membrane-bound organelles. Allows the internal and external environments to be different.
2. Regulation of exchange of substances - via its semi-permeable membrane.
3. Communication with the environment - the glycocalyx provides cell-to-cell recognition whereas the protein receptors are able to receive chemical messengers from other parts of the body.
4. Structural support - anchor proteins anchors cell to the extracellular matrix.

Question 15

Main components of the plasma membrane

Answer 15

1. Phospholipids
2. Carbohydrates
3. Proteins
4. Cholesterol

Question 16

3 major LIPIDS in the plasma membrane.

Answer 16

1. Phospholipids (phosphoglycerides)
2. Sphingolipids
3. Sterols (cholesterol)

Question 17

3 most abundant PHOSPHOGLYCERIDES that provide structure to the plasma membrane

Answer 17

1. Phosphatidylethanolamine
2. Phosphatidylserine
3. Phosphatidylcholine

Question 18

Types of proteins in the plasma membrane

Answer 18

1. Transporters
2. Anchors
3. Receptors
4. Enzymes

Integral - physically inserted into the membrane. Can be partially inserted or a transmembrane.
Peripheral - attached through integral protein or through the lipid in the membrane (called lipid anchored)

Question 19

Functions of the glycocalyx

Answer 19

1. Cell-to-cell recognition
2. Plasma membrane protection
3. Immunological roles