Cells

Question 1

Explain the function and structure of mitochondria

Answer 1

Releases energy from glucose during aerobic respiration by production of ATP
Inner, outer membrane
cristea- extension of membrane/folds provide large SA
matrix- cytoplasm like substance containing enzymes involved in respiration, circular DNA and ribosomes to make own proteins

Question 2

Explain the function and structure of chloroplasts

Answer 2

Absorb light energy for photosynthesis for glucose
Grana- stack of thylakoid
Thylakoid-contains chlorophyl joined by inter granal lamallae
starch grains- stores of starch
stroma- fluid containing enzymes
contains dna and ribosomes to make own proteins

Question 3

Explain the process of protein synthesis

Answer 3

Rough endoplasmic reticulum with ribosomes forms ppc and pass through
membrane begins to bud off towards golgi apperatus and fuses the membrane releasing the ppc to mould into useful protiens and secreted

Question 4

what is the function of golgi body

Answer 4

process modify and package proteins

Question 5

what is the function of the rough endoplasmic reticulum

Answer 5

transport protein chains towards golgo

Question 6

what is the function of the soft endoplasmic reticulum

Answer 6

transport lipids and carbohydrates

Question 7

what is the cell membrane made from

Answer 7

phospholipids and proteins to control the movement of substances

Question 8

what is the function of lysosomes

Answer 8

vesicle containing digestive enzymes to digest unwanted materials

Question 9

What are differences between pro and eukaryotic cells

Answer 9

pro- smaller, no membrane bound organelles, 70s ribosomes, no nucleus, has a cell wall made of murein ( a glycoprotein), plasmids, capsule, flagella, pili

Question 10

how are viruses describes

Answer 10

acellular- none living since depend on host cells to live and reproduce
attachement proteins (glycoproteins)
enzymes- convert rna to dna
lipid envalope-
capsid-protein coat
much smaller than bacteria

Question 11

Explain the types of viral replications

Answer 11

Lyctic- the viral cell will attach onto a host and penetrate into the cell, viral genetical material enters nucleus and is copied by host cell enzymes continuously, new virus particles will bud off taking part of cell membrane and cell bursts
Lysogenic- attaches and enters, using enzymes will convert rna to dna to be undetected and enter nucleus and replicate.

Question 12

Describe cell devision in prokaryotes

Answer 12

called binary fission:
circular dna and plasmids will replicate
cell membrane will grow and pinches inwards to divide the cytoplasm in two
a new cell wall forms to give two identical daughter cells

Question 13

Explain the process of the cell cycle in detail

Answer 13

Interphase- DNA duplicate and cells grow in preparation, chromosomes not seen
Prophase- nuclear envelope breaks down, spindle fibres form, chromosomes can be seen x shape
Metaphase- spindle fibres attach to centromere of each chromosomes and line in centre
Anaphase- spindle fibres contract and pull apart the chromatids
Telophase- new nuclear envelopes form, divides
Cytokinesis- cytoplasm splits, cell membrane joins

Question 14

Explain phases of cell cycle and time taken to complete

Answer 14

interphase 23 hours- G1 cell increases in size, S DNA replicates, G2 cell organelles increase
mitosis 1 hour

Question 15

Explain the process of cell fractionation to study cells

Answer 15

homogenisation sample, break up the cell
filter intact parts of cells
ultracentrifugation to separate out organelles

Question 16

explain the details of homogenisation

Answer 16

the sample is broken down to open cell membrane and placed in a cold isotonic buffer
cold-slow down enzyme activity
isotonic- so water does not enter or leave by osmosis so it doesnt shrivel or burst
buffer- maintain a constant pH preventing denaturing proteins

Question 17

what is the supernatant

Answer 17

a pellet of light organelles that are at the top of the tube