Topic 2 - Cells

Question 1

What are the components of the nucleus?

Answer 1

Nuclear pores - allow RNA to leave
Nuclear envelope - keep DNA contained
Chromatin - genetic information
Nucleolus - makes RNA
Nuclearplasm

Question 2

What do centrioles do?

Answer 2

Make spindle fibres for cell division

Question 3

What does the roughy endoplasmic reticulum do?

Answer 3

Site of protein synthesis, packages proteins into vesicles

Question 4

What kind of ribosomes are present in animal cells and what do they do?

Answer 4

80s ribosomes - site of protein synthesis

Question 5

What does the smooth endoplasmic reticulum do?

Answer 5

Makes and packages lipids and carbohydrates into vesicles

Question 6

What does the Golgi apparatus do?

Answer 6

Modifies and packages molecules from SER and RER into either a secretory vesicles or a lysosome

Question 7

What are lysosomes and secretory vesicles?

Answer 7

Lysosome - stores hydrolytic enzymes for phagocytosis
Secretory vesicles - fuses with cell membrane and releases contents (exocytosis)

Question 8

What is the cell wall in a plant cell?

Answer 8

Made up of cellulose and pectin
Completely permeable
Prevents cell from bursting under osmotic pressure

Question 9

What happens in the mitochondria?

Answer 9

Aerobic respiration

Question 10

What does the large permanent vacuole in a plant cell do?

Answer 10

Stores water and pigment etc
Maintains turgidity

Question 11

What are amyloplasts and chloroplasts?

Answer 11

Amyloplast - storage of starch
Chloroplast - site of photosynthesis
They can become each other

Question 12

What are the components in a mitochondrion?

Answer 12

70s ribosomes
Plasmids
Matrix - contains enzymes for respiration
Outer membrane
Inner membrane - tightly folded into cristae to increase SA
Cristae - structure of inner membrane

Question 13

What are the components of chloroplasts?

Answer 13

Starch grains - to become an amyloplast
Plasmid
70s ribosomes
Stroma (the chloroplasts cytoplasm)
Granum- stacked thylakoid membranes
Lamella - link granum together

Question 14

What is the flagellum for in bacteria cells?

Answer 14

Locomotion and movement

Question 15

What is the pila for in bacteria cells?

Answer 15

Enable interactions with host - for adherence to surfaces

Question 16

What are the 2 types of DNA in bacteria cells?

Answer 16

Plasmid DNA - contains genes and help bacteria survive adverse conditions
Circular DNA - contains genetic information

Question 17

What kind of ribosomes are in bacteria cells?

Answer 17

70s ribosomes

Question 18

What is the mucilaginous slime capsule for in bacteria cells?

Answer 18

Protection and preventing desiccation and prevents phagocytosis

Question 19

What is the capsid in viruses?

Answer 19

A protein coat

Question 20

What is in the capsid in viruses?

Answer 20

Nucleic acid
Reverse transcriptase (only in retroviruses(with RNA))

Question 21

What are attachment proteins in viruses for?

Answer 21

Identify and attach to host cells

Question 22

What are the components of viruses?

Answer 22

Attachment proteins
Lipid envelope
Matrix proteins
Matrix
Capsid
Nucleic acid
Reverse transcriptase

Question 23

How do DNA viruses replicate?

Answer 23

Attach to receptors on host cell
Inject Nucleic acid which then inserts into chromosomes
Ribosomes then make viral proteins which form new viruses
New viruses burst cell and spread

Question 24

How do retroviruses replicate?

Answer 24

Attaches to host cell
Inserts Nucleic acid and reverse transcriptase which makes DNA copy of viral DNA
This is inserted into chromosomes
Proteins make viral proteins
New viruses burst cell and spread

Question 25

What are the steps of binary fission?

Answer 25

All DNA is replicated Circular DNA molecules attach to plasma membrane Cell elongates to separate circular DNA Cell cleaves in two identical daughter cells

Question 26

What are the five stages of the cell cycle?

Answer 26

Gap 1 Synthesis - all 3 = interphase Gap 2 Mitosis Cytokinesis

Question 27

What happens in gap 1 and 2 of mitosis

Answer 27

Protein synthesis Cytoplasm grows Energy stores increase ATP synthesis Organelles replicate

Question 28

What happens in synthesis?

Answer 28

Semi conservative DNA replication

Question 29

What are the 4 stages of mitosis?

Answer 29

Prophase Metaphase Anaphase Telophase

Question 30

What happens in prophase?

Answer 30

Chromosomes condense and become shorter and thicker Nucleolus and nuclear membrane break down Centrioles move to opposite poles and form spindle fibres

Question 31

What happens in metaphase?

Answer 31

Spindle fibres complete Each centromere attaches to a spindle fibre from each pole Chromosomes line up on equator

Question 32

What happens in anaphase?

Answer 32

Spindle fibres contract and shorten Centromeres split Chromosomes split Chromatids separate and are pulled to opposite poles centromere first

Question 33

What happens in telophase?

Answer 33

Identical sister chromatids real poles and unwind to become chromosomes New nuclear envelopes forms

Question 34

What are the components of the cell membrane?

Answer 34

Phospholipid bilayer Cholesterol Intrinsic proteins Extrinsic proteins Glycolipids Glycoproteins

Question 35

What is the use of the phospholipid bilayer?

Answer 35

It is impermeable to most substances e.g. polar molecules (glucose and amino acids) and ions (are repelled by hydrophobic FA tails) It is permeable to lipid soluble molecules and small uncharged molecules (O2 + CO2)

Question 36

What is the use of cholesterol in the cell membrane?

Answer 36

Dissolved into FA tails Helps stabilise membrane Makes less fluid at higher temperatures

Question 37

What intrinsic proteins do ions travel through?

Answer 37

Intrinsic channel proteins Travel using facilitated diffusion

Question 38

What intrinsic proteins do polar molecules travel through?

Answer 38

Intrinsic carrier proteins Travel using facilitated diffusion

Question 39

What are the uses of glycolipids glycoproteins and extrinsic proteins in cell membranes?

Answer 39

Cell markers (antigens) Receptors

Question 40

What does the cell membrane do?

Answer 40

Prevents substances passing through Separates contents of cells Allows certain substances through Cell signalling