Cell Structure - Topic 2.a

Question 1

What does the nucleus contain and what does it do?

Answer 1

DNA
Transmits genetic material to the cell for protein synthesis

Question 2

What does the outer membrane of the nuclear envelope do?

Answer 2

Connect to the endoplasmic reticulum

Question 3

What do the cristae do in the mitrochondria?

Answer 3

Increase surface area to allow for more aerobic respiration

Question 4

The mitrochondria has a double membrane. What does each one do?

Answer 4

Outer membrane- controls what enters and exits
Inner membrane- folds into cristae

Question 5

What do the nuclear pores do?

Answer 5

Allow large molecules to enter and exit

Question 6

What does the nucleus contain?

Answer 6

Nucleolus
Chromatin
Nucleoplasm
Nuclear pores
Nuclear envelope

Question 7

What does the nucleolus do?

Answer 7

Make ribosomes

Question 8

DNA in the nucleoplasm in the form of unwound chromosomes is what?

Answer 8

Chromatin

Question 9

What green pigment makes leaves green and what does it do?

Answer 9

Chlorophyll - helps to absorb sun for photosynthesis

Question 10

What ribosome size do eukaryotic cells have?

Answer 10

80s

Question 11

What does the smooth endoplasmic reticulum do?

Answer 11

Lipid and carbohydrate synthesis

Question 12

What are cisternae and where are they found?

Answer 12

Sheet-like membranes spreading throughout the cytoplasm
Found in both the smooth and rough endoplasmic reticulum

Question 13

Why does the RER have a large surface area?

Answer 13

So more ribosomes can attach and more proteins can then be made

Question 14

Are ribosomes membrane bound or non-membrane bound?

Answer 14

They are a non-membrane bound organelle

Question 15

What organelle is responsible for protein synthesis?

Answer 15

Ribosomes

Question 16

What do plant cells have that animal cells don’t?

Answer 16

Vacuole
Cell wall made of cellulose
Chloroplasts

Question 17

What type of cell is bacteria?

Answer 17

Prokaryote

Question 18

Animal and plant cells are what type of cells?

Answer 18

Eukaryotic

Question 19

Fungal cells are the same as plant cells apart from what?

Answer 19

Have no chloroplasts

Question 20

Do viruses have organelles?

Answer 20

No

Question 21

What is the cell wall of bacteria made from?

Answer 21

Meurein

Question 22

What is the cell wall of fungi made from?

Answer 22

Chitin

Question 23

What are plant cell walls made from?

Answer 23

Cellulose

Question 24

What is the Golgi made up of?

Answer 24

Stack of membranes (cisternae)

Question 25

What does the Golgi apparatus do?

Answer 25

Sorts, modifies, packages and secretes proteins

Question 26

When part of the cisternae in Golgi bud of what is formed?

Answer 26

Vesticles

Question 27

What do vesticles do?

Answer 27

Transport substances across the cell

Question 28

How are lysosomes formed?

Answer 28

By budding off the Golgi apparatus

Question 29

What enzymes do lysosomes contain?

Answer 29

Hydrolytic enzymes- break down molecules by hydrolysis Digestive enzymes- break down harmful materials

Question 30

What size are the ribosomes in prokaryotes?

Answer 30

70s

Question 31

What shape is the DNA in prokaryotes?

Answer 31

Circular- doesn't form chromosomes

Question 32

What plasmid and what cell type is it found in?

Answer 32

Small loops of DNA Bacteria -which is a prokaryote

Question 33

What is the region of the cytoplasm that contains DNA called?

Answer 33

Nucleoid

Question 34

What is the cell membrane of prokaryotes made up of?

Answer 34

Phospholipids and proteins

Question 35

What's a mesosome and its function?

Answer 35

Infolded membranes to increase surface area for more acellular respiration

Question 36

What a capsule?

Answer 36

Goes around outside of the cell wall of bacteria (prokaryote) to protect it from phagocytosis

Question 37

What helps viruses to enter a host cell?

Answer 37

Attachment proteins

Question 38

What the capsid in viruses ?

Answer 38

A protective protein coat that surrounds the viral genetic material

Question 39

Viruses are non living. What does this mean?

Answer 39

They can't reproduce on their own (they're acellular)

Question 40

What's a viron?

Answer 40

A complet virus particle

Question 41

How do bacteria reproduce?

Answer 41

Binary fission: Circular DNA & plasmids replicate Cell grows & DNA loop moves to opposite poles of the cell Cytoplasm begins to divide & new cell wall begins to form Cytoplasm splits - two daughter cells are produced

Question 42

How do viruses reproduce?

Answer 42

Viral replication: Virus attached to host cells receptor proteins Virus penetrates its genetic material into host cell Genetic material is replicated by the host cells machinery Viral components assemble Replicated viruses release from the host cell

Question 43

What is cell fractionation?

Answer 43

Where cells are broken up so the different organelles inside are exposed

Question 44

What will form the pellet at a low speed spin in ultracentrifugation?

Answer 44

Most dense organelles- nuclei

Question 45

What will form the pellet at a high speed spin during ultracentrifugation?

Answer 45

Least dense organelles- ribosomes

Question 46

What does homogenation do in the process of cell fractionation?

Answer 46

Breaks down the cell wall / membrane to expose the organelles

Question 47

What does a homogeniser do?

Answer 47

'Blend' the tissue to form a homogenate- the resultant fluid

Question 48

What does a centrifuge do?

Answer 48

Spins test tubes with the homogenate in

Question 49

Why is the homogenate filtered in the process of cell fractionation?

Answer 49

To remove any cellular debris

Question 50

What is a supernatant, in cell fractionation?

Answer 50

The fluid that is re-spun to separate less dense organelles

Question 51

Why is tissue placed in a cold, isotonic buffer solution, in cell fractionation?

Answer 51

Cold- reduce enzyme activity, that would break down organelles Isotonic- to keep the same water level inside and outside of the cells= prevent osmosis= stops cell from bursting Buffer- maintain constant pH= prevent proteins from denaturing

Question 52

Advantages of using a light microscope

Answer 52

Can see live specimen Portable Cheaper

Question 53

Disadvantages of using a light microscope

Answer 53

Limited resolution and magnification Have to use a stain to make the specimen visible- transparent otherwise

Question 54

What's an artefact?

Answer 54

Something seen through a microscope that shouldn't be there (fingerprint)

Question 55

Advantages of using a transmission electron microscope

Answer 55

Produced detailed 2D image of inside the cell Can see organelles Highest magnification- x50million

Question 56

Disadvantages of using a transmission electron microscope

Answer 56

Specimen must be really thin Time consuming to set up Specialist training required to use it Specimen must be dead

Question 57

Advantages of using a scanning electron microscope

Answer 57

Produces a detailed 3D image of the surface of tissues Samples don't have to be very thin Little sample prep Easier to use

Question 58

Disadvantages of using a scanning electron microscope

Answer 58

Specimen must be dead Needs to be coated in metal

Question 59

The equation for magnification:

Answer 59

Magnification= image size ÷ actual size

Question 60

What is magnification?

Answer 60

Making an image of an object larger than the object really is