Cell Structure

Question 1

what does the attachment protein do on a virus?

Answer 1

proteins used by virus to identify + attach to host cells

Question 2

what is the role of the capsid on a virus?

Answer 2

encloses 2 single strands of RNA + enzymes.

Question 3

The genetic material in a virus?

Answer 3

contains genetic material to reproduce

Question 4

role of the lipid envelope on a virus?

Answer 4

have attachment proteins

Question 5

what is the matrix in a virus?

Answer 5

layer of proteins situated under outer envelope

Question 6

what is the role of reverse transcriptase in a virus?

Answer 6

catalyses production of DNA from RNA

Question 7

what are the ribosomes in bacteria? + their role

Answer 7

70s ribosomes. polypeptide synthesis

Question 8

role of nucleoid (circular DNA) in bacteria?

Answer 8

processes genetic info

Question 9

role of plasmids in bacteria?

Answer 9

codes for antibiotic resistant properties, can be transfered to other cells

Question 10

role of the slime capsule in bacteria? (3)

Answer 10

• prevents drying out
• prevent being engulfed by white blood cells
• helps group bacteria together

Question 11

role of the cell wall in bacteria?

Answer 11

• gives cell strength
• prevents osmotic lysis
• prevents certain substances from entering

Question 12

what is the cell wall made out of in a bacteria cell?

Answer 12

meurin (glycoprotein)

Question 13

role of flagellum (prokary)

Answer 13

rotates/propels the cell, directional movement

Question 14

All life on Earth exists as cells. These have basic features in common. Differences between cells are due to the addition of extra features. What does this provide evidence for?

Answer 14

This provides indirect evidence for evolution

Question 15

1. All cells have a cell-surface ________ + eukaryotic cells have _______ membranes.
2. The basic structure of these ______ membranes is the same + enables control of the passage of
   _________ across exchange surfaces by ______ or active transport.

Answer 15

1. membrane, internal,

2. plasma, substances, passive

Question 16

1. Cell-surface membranes contain ______ proteins. Some of these are involved in cell _______/ communication between cells.
2. Others act as _______,
3. Interactions between different types of cell are involved in disease, ________ + prevention of symptoms occurring later if exposed to the same ______

Answer 16

1. embedded, signalling
2. antigens
3. recovery, antigen

Question 17

what is the definition of a cell? and 3 examples

Answer 17

membrane bound structure, contains biomolecules

i.e. sperm, neurone, nerve

Question 18

What is the definition of a tissue? and 3 examples

Answer 18

a group of similar cells working together to carry out a specific function
i.e. epithelial cells, xylem, elastic fibres

Question 19

what is the definition of an organ? and 3 examples

Answer 19

combination of different tissues working together to carry out a variety of functions
i.e. Aorta, vein, palisade layer

Question 20

how does cell specialisation/organisation occur?

Answer 20

1. all somatic cells same genes
2. specialised by some genes being expressed
3. cells adapted to own particular function = efficiently functions

Question 21

Function of cell surface membrane

Answer 21

• allows different conditions to be established in/out of cell
• controls movement of substances in/out of cell

Question 22

name the 5 different components of the cell surface membrane

Answer 22

phospholipids, proteins, glycolipids, glycoproteins, cholesterol

Question 23

Eukaryote: name the 4 components of the nucleus

Answer 23

1. nuclear envelope
2. nuclear pores
3. chromatin
4. nucleolus

Question 24

Eukaryote: name the 3 components of mitochondria + their role

Answer 24

1. cristae: increase SA for attachment of enzymes for respiration
2. Double membrane: controls entry/exit of stuff
3. matrix: contains proteins, lipids, ribosomes, DNA

Question 25

Eukaryote: name the 3 components of chloroplasts + their function

Answer 25

1. chloroplast envelope: (double membrane) highly selective 2. Grana (stack to make thylakoids): contain chlorophyll + absorb light (LDR) 3. stroma: matrix, synthesis of sugars (LIR)

Question 26

How is chlorophyll adapted to to their function?

Answer 26

- granal membranes increase SA for electron carries/ enzymes - fluid of stroma possesses all enzymes needed - contain DNA + ribosomes = synthesise proteins for photo

Question 27

Eukaryote: role of RER

Answer 27

- provide large SA for synthesis of proteins/glycoproteins | - a pathway for transport of materials

Question 28

Both SER and RER have ________ and are continuous with the _______ envelope. BUT RER has ________!!

Answer 28

cisternae, nuclear, ribosomes

Question 29

Eukaryote: role of SER

Answer 29

synthesise, transport and store lipids/carbohydrates

Question 30

eukaryote: roles of mitochondria (2)

Answer 30

- site of aerobic respiration | - produces ATP from carbohydrates

Question 31

Eukaryote: roles of nucleus (3)

Answer 31

- synthesise mRNA + tRNA (protein synthesis) - retain genetic material - manufacture rRNA + ribosomes

Question 32

Eukaryote: roles of the golgi apparatus/vesicles (4)

Answer 32

- combine carbohydrates + proteins = glycoproteins - produces secretory enzymes - transport, modify + store lipids - form lysosomes

Question 33

Eukaryote: what is the golgi made up of?

Answer 33

cisternae and vesicles (pinched off golgi + transports substances)

Question 34

Eukaryote: what are lysosomes made up of?

Answer 34

- formed when vesicles contain enzymes | - contain different hydrolytic enzymes (lysozymes)

Question 35

Eukaryote: roles of the lysosomes (4)

Answer 35

- hydrolyse material ingested by phagocytic cells - release enzymes (exocytosis) destroy material - digest worn out organelles + autolysis - hydrolyse cell wall of bacteria

Question 36

T or F: 70s ribosomes are present in eukaryotes and 80s are present in prokaryotes

Answer 36

F. 80s = eukary 70s = prokary

Question 37

what is the structure + function of a ribosome?

Answer 37

- tiny cytoplasmic granules made from 2 sub units (small = large) - site of protein synthesis

Question 38

Eukaryotes (plants, algae, fungi): what is the cell wall made up of?

Answer 38

- microfibrils: polysaccharide cellulose = gives strength | - middle lamella: cements adjacent cells together + marks boundary between adjacent cells

Question 39

eukaryotes: role of the cell wall (3)

Answer 39

- mechanical strength (no lysis under osmotic pressure) - give strength to plant as a whole - allow H2O to pass along it

Question 40

T or F: algae cell walls can be made up of cellulose and/or glycoproteins

Answer 40

true

Question 41

what are the cell walls in fungi made up of?

Answer 41

chitin

Question 42

Eukaryotes: structure of the vacuole

Answer 42

- has a single membrane called a tonoplast | - contains salts, sugars, amino acids, wastes, pigments

Question 43

role of the vacuole?

Answer 43

- give strength (turgid) - sugars/amino acids temporary food store - pigments attract pollinators

Question 44

in prokaryotic cells, the organelles are NOT...

Answer 44

membrane bound

Question 45

viruses are _______ and non-______.

Answer 45

acellular and are non-living

Question 46

Prokaryotic DNA is not associated with_______ proteins and have no ______

Answer 46

histone, introns

Question 47

What is the role if the nucleolus in eukaryotic cells? (2)

Answer 47

- synthesises ribosomal RNA | - assembles ribosomes

Question 48

What are the 2 roles of the nuclear envelope?

Answer 48

1. contains reactions taking place | 2. control of entry