Cell Structure

Question 1

what is the powers for the following units:
kilo, milli, micro, nano

Answer 1

kilo - 10^3
milli - 10^-3
micro - 10^-6
nano - 10^-9

Question 2

how do you calculate magnification

Answer 2

image size / actual size

Question 3

what is cell fractionation

Answer 3

the process of seperating cell organelles from eachother

Question 4

what is ultracentrifugation

Answer 4

the cells in a sample being broken open via being spun at high speeds for a certain time to seperate the organelles.

Question 5

what are the steps to seperate cells by there mass (5)

Answer 5

1. crush the cells with a blender
2. filter to remove cell debris (makes a cell homogenate)
3. pour into a test tube and spin in a centrifuge
4. pour supernatent and respin at a higher speed.
5. repeat ro get lighter organelles

Question 6

what is the solid / liquid called that forms from celll centrifugation

Answer 6

solid - pellete
liquid - supernatent

Question 7

what are the 3 test conditions for cell centrifugation and why must they be maintained

Answer 7

• cold temp so enzymes don’t denature and stops enzyme activity due to a drop in KE
• control the pH to avoid protein damage
• control the water potential to prevent osmosis

Question 8

what type of microscope cana observe living and non living specimens

Answer 8

light

Question 9

which microscope produces a 3D image

Answer 9

Scanning electron microscope

Question 10

how does a scanning electron microscope work

Answer 10

electrons are reflecterd from the surface on the specimen and then these are detected

Question 11

how does a transmission electron microscope work

Answer 11

electrons pass through the specimen and then theyre detected

Question 12

what are artefacts

Answer 12

dust or air bubbles

Question 13

what stain must be used for plants and what for animals

Answer 13

plants - iodine solution
animals - methelyne blue

Question 14

what is an eyepiece graticule

Answer 14

an eyepiece with a transparent ruler with numbers but no units

Question 15

what is a stage micrometer

Answer 15

a microscope slide with an accurate scale with units which is placed in a microscope slide

Question 16

how do you use the eyepiece graticule and stage micrometer

Answer 16

1 - callibrate the two by lining the 0 on the eyepiece graticule with one of the stage micrometer divisions
2 - see how many intervals on the eyepiece graticle is equal to one interval on the stage micrometer
3 - divide the value of one stage micrometer interval by the number of eyepiece graticule intervals its equal to

Question 17

what are the 4 components of the nucleus

Answer 17

nucleur pore
membrane bilayer
DNA
nucleuolus

Question 18

what are histone proteins

Answer 18

round proteins that DNA wraps around - makes it compact

Question 19

what do nucleur pores do

Answer 19

allow controled exchanged between the nucleus and cytoplasm

Question 20

what are the 5 components of the mitochondria

Answer 20

inner membrane
outer membrane
inter membranal space
matrix
cristae

Question 21

where does aerobic respiration take place in the mitochondria

Answer 21

the matrix and on the cristae

Question 22

what is the size of ribosomes in a eukaryotic / prokaryotic cell

Answer 22

eukaryotic - 80s
prokaryotic - 70s

Question 23

what is the rough endoplasmic reticulum and what does it do

Answer 23

extended system of membrane sacs that is covered in ribosomes

transports and synthesises proteins

Question 24

what is the smooth endoplasmic reticulum and what does it do

Answer 24

a system of membrane sacs, but no ribosomes

synthesis and transports lipids, steroid, hormones and carbohydrates (also stores carbs)

Question 25

what is the golgi apparatus and what does it do

Answer 25

a stack of flattened membranes modifies proteins makes lysomes collects and sorts molecules, that are then transported in golgi vesicles to other parts of the cell or theyre exocyted

Question 26

what can golgi vesicles store

Answer 26

enzymes

Question 27

what are lysosomes and what do they do

Answer 27

a vesicle which contains hydrolytic enzymes such as lysozymes

Question 28

what makes up the cell wall in plants / fungi / algae

Answer 28

plants - cellulose fungi - chitin algae - cellulose or glycoproteins

Question 29

how permeable are cell walls

Answer 29

fully

Question 30

what are the 7 components of the chloroplast

Answer 30

stroma (internal fluid) intergranal lamellae granum thylakoids inner membrane outer membrane starch grains

Question 31

what is a stack of thylakoid discs called

Answer 31

grana

Question 32

what stores cell sap in the permanent vaculoe

Answer 32

tonoplast

Question 33

name all the animal cell organelles (9)

Answer 33

nucleous ribosomes cell membrane cytoplasm mitochondria golgi apparatus + vesicles lysosomes smooth endoplasmic reticulum rough endoplasmic reticulum

Question 34

name all the plant cell organelles (12)

Answer 34

nucleous ribosomes cell membrane cytoplasm mitochondria cell wall permanent vacuole chloroplasts golgi apparatus + vesicles lysosomes smooth endoplasmic reticulum rough endoplasmic reticulum

Question 35

what are the four main human tissues

Answer 35

epithelial connective muscular nervous

Question 36

what does epithelial tissue do

Answer 36

protect organs by lining there surface

Question 37

what are the 5 main plant tissues

Answer 37

palisade mesophyll spongey mesophyll epidermis xylem phloem

Question 38

what is the function of the xylem

Answer 38

transports water and mineral ions throughout the plant, whilst also offering mechanical support

Question 39

what is the order of cell organisation

Answer 39

cells tissues organs systems organisms

Question 40

what are the organelles found in a prokaryotic cell (7)

Answer 40

ALL HAVE cytoplasm 70s ribosomes circular loop of DNA cell wall SOME HAVE plasmids capsule flagella

Question 41

what is a prokaryates cell wall made of

Answer 41

murein - a glycoprotein

Question 42

what is the role of the capsule in prokaryates

Answer 42

protects the cell and allows adhesion

Question 43

are viruses a prokaryate

Answer 43

no theyre not cells (acellular)

Question 44

what are the components of viruses (4)

Answer 44

DNA / RNA proteins capsid attatchment proteins enzymes

Question 45

what is the name for bacterial mitosis (asexual reproduction)

Answer 45

binary fission

Question 46

what is the process of binary fission

Answer 46

circular DNA and plasmids undergo DNA replication cell then divides into 2 new identical cells

Question 47

how do viruses replicate (5)

Answer 47

1 - attatchment proteins on the virsus surface attach to a host cells complementary reseptors 2 - virus then enters the cell and uncoats to release its own DNA 3 - virus DNA is replicated by the host 4 - virus uses the hosts protein synthesising system 5 - releases new viruses to affect other cells

Question 48

what are the 3 sections of interphase

Answer 48

G1 - cell increases in size and new organelles are made S - DNA synthesis G2 - further increase in size and new organelles made

Question 49

what are the 4 phases of mitosis

Answer 49

prophase metaphase anaphase telephase

Question 50

what is it called when the cell splits

Answer 50

cytokinesis

Question 51

what are the 6 parts of a chromosome

Answer 51

chromosome chromatid centromere DNA chromatin histone

Question 52

what is one strand of the chromosome called

Answer 52

chromatid, the two together are sister chromatids

Question 53

what are chromatins

Answer 53

uncoiled DNA and histones

Question 54

what holds the chromosome together

Answer 54

centromere

Question 55

how many chromosomes do humans have

Answer 55

46

Question 56

is coiled or uncoild DNA visable

Answer 56

coiled

Question 57

what happens during prophase (3)

Answer 57

- supercoiling - DNA wraps around histones - Nucelur envelope dissapears

Question 58

what happens during metaphase

Answer 58

all copied chromosomes align themselves around the equator (92), held there by the spindle apparatus

Question 59

what happends during anaphase

Answer 59

chromsomes split and migrate to opposing poles, led by the centromere

Question 60

what happens during telephase (3)

Answer 60

cell begins to spilt nucleur envelope beings to reform DNA starts to uncoil

Question 61

what is cancer

Answer 61

uncontrollable cell division which is caused by a gene mutation

Question 62

what controls the rate of cell division

Answer 62

genes

Question 63

what are the 3 types of cancer treatment

Answer 63

chemotherapy radiotherapy immunotherapy

Question 64

what do most cancer treatments aim to do

Answer 64

controlling the rate of cell division by disrupting the cell cycle