Cell Biology

Question 1

Label as many features in a mammalian cell as you can.

Answer 1

SER
RER
NUCLEUS, nucleolus
Mitochondrion 
Plasma membrane
Golgi apparatus 
Cytoplasm
Ribosome
Centrosome
Peroxisome
Lysosomes
Cytoskeleton: microfilaments, intermediate filaments, microtubules.

Question 2

What structures aren’t found in animal cells but found in others

Answer 2

Chloroplasts.
Cell wall
Central vacuole and tonoplast
Cell wall
Plasmodesmata

Question 3

3 constituents of cytoplasm

Answer 3

Microfibrils
Intermediate filaments
Microtubules

Question 4

3 types of cell junction

Answer 4

Tight junction
Gap junction
Desmosome

Question 5

Function of centrosome

Answer 5

Made of two centrioles - organise microtubules and provide structure for the cell.

Question 6

Function of peroxisome

Answer 6

Break down long fatty acid chains via beta oxidation into smaller fatty acids to be used in metabolic pathway

Question 7

Function of Golgi apparatus

Answer 7

Modifying, sorting and packaging of proteins for secretion.
the transport of lipids around the cell.
Creation of lysosomes

Question 8

Function of mitochondria

Answer 8

Create energy by breaking down nutrients/food, in the form of ATP.
Carry out cellular respiration.

Question 9

Function of lysosome

Answer 9

Membrane bound vesicles containing digestive enzymes to digest run down or excess organelles and food and anything else that needs to be removed from cell.

Question 10

Function of ribosome

Answer 10

Protein synthesis

Question 11

Function of SER

Answer 11

Produce hormones lipids etc

Question 12

4 things optical microscopy uses to enable shape and organisation to be viewed?

Answer 12

Cell staining
Phase contrast techniques
Immunostaining
Fluorescence staining

Question 13

What has the highest resolution microscope

Answer 13

SRM - 250nm

Question 14

Different stains and function

Answer 14

DAPI- fluorescent nuclear stain for DNA.
Eosin-counter stain haematoxylin pink or red with proteins.
Hematoxylin- nuclear stain - blue-violet brown

Question 15

6 categories of cell types

Answer 15

Nerve cells
Gland cells
Blood cells 
Muscle cells
Bone/skeletal cells
Reproductive cells

Question 16

Plasma membrane function

Answer 16

Separate extracellular from intracellular - protect

Regulates the movement of substances in and out of cells.

Question 17

Where are ribosomes made?

Answer 17

Assembled in nucleolus.

Four rRNA strands create 2 subunits.

Question 18

4 enclosed cell compartments organelles

Answer 18

ER - rough and smooth.
Golgi apparatus.
Lysosomes/vacuoles.
Trafficking vesicles

Question 19

3 enzymes found in lysosomes

Answer 19

Proteases,
Glycosidases
Lipases
Many more

Question 20

Disease caused by lysosomal function defect

Answer 20

Lysosomal storage disease

Question 21

2 unusual things about chloroplasts and mitochondria compared to other organelles

Answer 21

1) own DNA(genome).

2. Secondary specialised inner membrane.

Question 22

Proposed origin of chloroplasts and mitochondria.

Answer 22

Symbiosis of bacteria and animal/plant cells.

Question 23

What % of a bacterial cell is water/protein/DNA/RNA/ions/phospholipids/polysaccharides?

Answer 23

Water - 70%
Protein - 15%
DNA - 1%
RNA - 6%
Ions & small molecules - 4%
Phospholipids - 2%
Polysaccharides - 2%

Question 24

What % of a eukaryotic cell is water/protein/DNA/RNA/ions/phospholipids/polysaccharides?

Answer 24

water - 70%
protein - 18%
DNA - 0.25%
RNA - 1.1%
ions & small molecules- 4%
phospholipids - 3%
polysaccharides - 2%

Question 25

How are proteins made?

Answer 25

- DNA unravelled in are chosen gene is located - template strand is used to form a complementary mRNA via transcription. - mRNA is moved into RER - nuclear export - where it is read 3 codons at a time causing complementary aminoacid is brought via tRNA, amino acid adjacent join to form peptide chain - translation

Question 26

Where does translation take place?

Answer 26

Ribosomes on RER

Question 27

Describe process of translation elongation

Answer 27

Ribosome has 3 sites A,P,E site. - methionine tRNA binds to p site. - the next tRNA binds to the A site. - peptide bond forms between two amino acids allowing ribosome to slide onto next codon. - 2nd tRNA now in p site. - next tRNA binds to a site and process carries on until a stop codon is read

Question 28

Where are many proteins synthesised?

Answer 28

Ribosomes on endoplasmic reticulum.

Question 29

What process is used to separate cells into their components?

Answer 29

Cell fractionation Centrifugation Isotope labelling can be used to follow compounds

Question 30

Using cell fractionation how do you isolate proteins associated with membranes?

Answer 30

Membranes float on top. | If treated with detergents - make them soluble and sediment profile can be examined to see shape and size of particles