Cell Structure Intro

Question 1

What is a cell and are they specialised?

Answer 1

A cell membrane structure consisting of 70% cytosol and various organelles

Question 2

What is protoplasm?

Answer 2

Cytoplasm + nucleus + cell membrane

Question 3

Three points of cell theory

Answer 3

1.cells are structural and organisational unit of life
2.All living things are composed of cells
3.All cells come from pre-existing cells

Question 4

How many cells in average human?

Answer 4

37.2 Trillion Cells within the average human

Question 5

What is the ratio of non-human to human cells?

Answer 5

3:1

Question 6

What is the main difference between prokaryotic and eukaryotic cells?

Answer 6

Eukaryotic cells have a nucleus

Question 7

Two differences in DNA between prokaryotes and eukaryotic cells

Answer 7

1.Prokaryotes: Naked, circular, no introns
2.Eukaryotes: bound to protein, linear, has introns.

Question 8

Two differences in organelles between prokaryotic and eukaryotic cells

Answer 8

1.prokaryotes:70s ribosomes, non-membrane bound
2.Eukaryotes: 80s, membrane bound

Question 9

Two differences between the size and reproduction between P and E cells

Answer 9

1.P: 1-5um, binary fission
2.E:10-100um, mitosis/meiosis

Question 10

What is the main difference between plant and animal cells?

Answer 10

Plant cells have a cell wall for support and are rectangular compared to rounder animal cells

Question 11

What organelles does a plant have that animals don’t?

Answer 11

Vacuole, Chloroplasts

Plants do not have centrioles, lysosomes

Question 12

What are the 4 main types of tissues in animals?

Answer 12

1.Muscle tissue
2.Nervous tissue
3.Epithelial tissue
4.Connective tissue

Question 13

What cell types are present in all cell types?

Answer 13

Cancer cells and stem cells

Question 14

Three types of muscle cells

Answer 14

1.Skeletal
2.Cardiovascular
3.Smooth

Question 15

Describe a Sarcomere

Answer 15

Sarcomere is a bundle made of thick myosin and actin filaments assembled by the Z and M lines (responsible for muscle contraction)

Question 16

Name two types of Neural cells

Answer 16

Neurons and neuralgia

Question 17

Two types of connective tissues

Answer 17

Connective proper
Specialised

Question 18

How far can the naked eye, light microscopes, and electron microscopes see?

Answer 18

Eye = 10^-4m
Light microscopy = 10^-7m
Electron Microscopy = 10^-10m

Question 19

Why are cells so small and abundant?

Answer 19

Surface area to volume ratio must be adequate to facilitate oxygen, nutrients, and waste

Question 20

What does increased epithelial surface area do?

Answer 20

Means increased area of absorption

Question 21

Name two types of light microscopy

Answer 21

1.Brightfield
2.Fluorescence microscopy

Question 22

Name two types of Electron microscopy

Answer 22

1.Scanning Electron Microscopy (SEM)
2.Transmission Electron Microscopy (TEM)

Question 23

Pros and cons of Brightfield Microscopy

Answer 23

It’s cheap and works on living cells

However lack of contrast, low res 0.2um, and staining is effort

Question 24

Pros and cons of Fluorescence microscopy

Answer 24

Living cells can be used, greater contrast, always improving and 3D confocal lenses

However low 0.2um res, staining is effort, kinda expensive too

Question 25

What nuclear stains are used in FM and what colour do they produce?

Answer 25

DAPI stains DNA into a blue/purple colour

Question 26

What cytoskeleton stains are used in FM and what colours do they produce?

Answer 26

Green for microtubules/MTOC and red for actin filaments

Question 27

Discuss immunisationing and GFP

Answer 27

Immunostaining is where dyed secondary antibodies attach to primary antibodies attached to a target cell. Green fluorescent proteins are acquired from jellyfish and can bind to any other gene, also many other colours have been created.

Question 28

What does scanning electron microscopy do?

Answer 28

Reveals topography of a sample however sample must be sputter-coated with an electron absorbing material like gold

Question 29

Pros and cons of SEM

Answer 29

Pros: Highest res, magnification still improving and less that 0.5 um is achievable Cons: Expensive, Effort, requires specialist knowledge, fixed specimens only, sensitive to vibration and electromagnetic fields

Question 30

What order is cell fractionation carried out in?

Answer 30

Pestle sample > strain for connective tissues > Spin for nuclei and unbroken cells > then mitochondria and lysosomes > then ribosomes, ER,golgi, and pieces of cell membrane

Question 31

What is cell biology about?

Answer 31

Microscopy, cell culture, cell staining, protein biochem, and molecular bio

Question 32

What are the two types of cell cultures?

Answer 32

Primary cultures and cell lines

Question 33

Pros and cons of primary cultures and cell lines

Answer 33

1. Primary cultures are derived from tissues and pros are they are real cells increasing accuracy, cons are costly and animal use means limited cell numbers 2.Cell lines are immortalised cell lineages and can be propagated in the lab indefinitely, pros are it’s cheap easy to manipulate and loads of cells, cons are a model system so may not give true results