Cell structure

Cell structure, methods of studying cells, mitosis

State all the components of an animal cell

1. cell membrane
2. extra cellular space
3. nucleus
4. nuclear pore
5. nuclear envelope/ membrane
6. nucleolus
7. endoplasmic reticulum
8. ribosomes
9. golgi apparatus/ body
10. cytoplasm
11. mitochondrion
12/14. cytoskeleton
13. temporary vacuole
15. centrioles
16. lysosomes

State all the components of a plant cell

1. chloroplasts
2. plasmodesmata
3. vacuole
4. cellulose cell wall
5. ribosomes
6. cell membrane
7. mitochondrion
8. golgi body
9. nucleus
10. nucleolus
11. smooth E.R
12. cytoplasm
13. rough E.R
14. nuclear membrane
15. vesicles

State the structure and function of the nucleus

1. It is double membraned (enveloped)
2. Contains nuclear pores which control exit of mRNA
3. It contains nucleolus- the site of ribosome production

State the structure and function of the endoplasmic reticulum

1. It is a series of membrane bound compartments
2. Smooth E.R- lipid and carbohydrate synthesis
3. Rough E.R- does protein sysnthesis

State the structure of the Golgi apparatus

1. A series of fluid filled, flattened and curved sacs
2. Processes and packages proteins and lipids
3. Produces lysosomes

State the structure and function of the mitochondria

1. They are oval shaped and double membraned
2. It is the site of aerobic respiration

State the structure and function of lysosomes

1. They are vesicles containing digestive enzymes bound by a single membrane

State all the components of a prokaryotic cell

1. cell wall
2. plasmid
3. ribosomes
4. flagella
5. pilli
6. cytoplasm
7. slime capsule
8. circular DNA chromosome
9. plasma, cell membrane

What is the cell wall of a prokaryote made of

Murein

State the function of the slime capsule

It provides a protective layer and prevents the cell from drying out

Describe the structure of viruses

They are non-living structures that consist of nucleic acid enclosed in a capsid

Describe a light microscope

Wavelength- 400-800nm
Imagery- direct
Resolution- 200nm
Radiation- light
Image- 2D/3D
Focused- lens
Magnification- x1000

Describe a scanning EM

Wavelength- 0.2nm
Imagery- indirect
Resolution- 0.1nm
Radiation- electron beams
Image- 3D
Focused- magnets
Magnification- x100000

Describe a transmission EM

Wavelength- 0.2nm
Imagery- indirect
Resolution- 0.1nm
Radiation- electron beams
Image- 3D
Focused- magnets
Magnification- x1,000,000,000

State the advantages and disadvantages of a light microscope

A- cheap, portable, easy to use, living things, colour
D- lower mag and res

State the advantages and disadvantages of a TEM and SEM

A- high mag and res,
D- expensive, long preparation, dead samples used, damages the specimen

Describe and explain the solution used in cell fractionation

1. It is cold- to reduce enzyme activity
2. Isotonic- stops the cells shrinking or bursting
3. Buffered- pH is stable

Describe the process of cell fractionation

1. Tissue is cut up and kept in a cold, buffered solution
2. The tissue is further broken up in a homogeniser
3. The tissue is further broken up in a ultra centrifuge at a low speed for 10 minutes (to separate nuclei)
4. It is then spun at medium speed (to seperate mitochondria)
5. Finally it is spun at a high speed (lysosomes)

State the 3 main phases of the cell cycle

Interphase, mitosis and cytokinesis

State the steps involved in interphase

G1- cells grow and organelles replicate
S- DNA is replicated
G2- cells grow more

State the steps involved in mitosis

Prophase, metaphase, anaphase, telophase

Define cytokinesis

When the cell splits in two to form 2 daughter cells

Describe interphase

1. Normal cell function occurs
2. Chromosomes are unwound at the chromatin

Describe prophase

1. Spindle fibres form- extend from centrioles and the centrioles migrate to poles of cells
2. Chromosomes condense
3. Nuclear envelope breaks down

Describe metaphase

1. Chromosomes align at the equator of the cell

Describe anaphase

1. Sister chromatids are separated by spindle fibres and pulled to opposite poles of the cell

Describe telophase

1. Chromosomes reach opposite poles and are enveloped by new nuclear membranes
2. Chromosomes unravel
3. Spindle fibres disintegrate