2.1.1 cell structures

Question 1

Plasma membrane

Answer 1

phospholipid bilayer that controls movement of substances in/out

found in all eukaryotic cells

Question 2

Cellulose cell wall

Answer 2

a cell wall made of cellulose that provides strength and support

found in plant cells

Question 3

Peptidoglycan cell wall and where it is found

Answer 3

a cell wall made of peptidoglycan that provides rigidity

found in prokaryotic cells

Question 4

Nucleus

Answer 4

organelle containing DNA
surrounded by the nuclear envelope covered in nuclear pores
contains a nucleolus that makes ribosomes

found in all eukaryotic cells (except erythrocytes)

Question 5

cytoskeleton

Answer 5

network of fibres within cytoplasm, made of microtubules and microfilaments

Question 6

Mitochondria

Answer 6

double bound by an envelope
folds in membrane called cristae with matrix inside to act as the site of aerobic respiration

found in all eukaryotic cells

Question 7

Ribosome

Answer 7

bound by a single membrane and contains digestive enzymes for protein synthesis

80s in eukaryotic cells
70s in prokaryotic cells

Question 8

Cytoplasm

Answer 8

site of all chemical reactions

found in all cells

Question 9

Vacuole

Answer 9

sac filled with water, nutrients and waste products to add rigidity

found in plant cells

Question 10

Chloroplast

Answer 10

double membrane bound sacs containing stroma for photosynthesis
has internal thylakoid membranes arranged in stacks to form grana linked by lamellae

found in plant cells

Question 11

Golgi apparatus

Answer 11

modifies and packages lipids and proteins into vesicles and produces lysosomes

found in all eukaryotic cells (except erythrocytes)

Question 12

Smooth endoplasmic reticulum

Answer 12

produces and processes lipids

found in all eukaryotic cells (except erythrocytes)

Question 13

Rough endoplasmic reticulum

Answer 13

covered in ribosomes and folds and processes proteins

found in all eukaryotic cells (except erythrocytes)

Question 14

Lysosome

Answer 14

vesicles full of digestive enzymes bound by a single membrane

found in animal cells

Question 15

Centriole

Answer 15

hollow ring of microtubules in a cylinder that is used in cell division to form spindle fibre
occurs in pairs to form centrosome

found in animal cells

Question 16

Circular DNA

Answer 16

contains genetic info

found in prokaryotic cells

Question 17

Mesosome

Answer 17

folds in the cell wall that produces ATP

found in prokaryotic cells

Question 18

Potential features of prokaryotic cells

Answer 18

flagellum
pili
plasmid
nucleoid
slime capsule

Question 19

What is magnification

Answer 19

degree to which the size of the image is larger than the size of the object

Question 20

What is resolution

Answer 20

degree to which you can distinguish between two very close points

Question 21

What is the equation for magnification

Answer 21

magnification = image size / actual size

Question 22

what are the features of a light microscope

Answer 22

cheap
poor resolution - long wavelength of light
can view live specimens
requires staining

Question 23

what are the features of all electron microscopes

Answer 23

expensive
can only view dead specimens
requires metal salts
high resolution

Question 24

what image does a transmission electron microscope produce

Answer 24

2D image of the inside of a cell

Question 25

what image does a scanning electron microscope produce

Answer 25

3D image of the outside surface of a cell

Question 26

what is the stain for DNA and what colour is it

Answer 26

acetic orcein dark red

Question 27

what is the stain for the cytoplasm and what colour is it

Answer 27

eosin pink

Question 28

what is the stain for lipids and what colour is it

Answer 28

sudan red red

Question 29

what is the stain for starch and what colour is it

Answer 29

iodine blue/black

Question 30

what is the stain for the nucleus and what colour is it

Answer 30

nile blue blue

Question 31

what are the steps for gram staining gram positive bacteria

Answer 31

apply crystal violet stain fix dye with iodine it will appear blue due to thick peptidoglycan cell wall

Question 32

what are the steps for gram staining gram negative bacteria

Answer 32

apply crystal violet stain fix dye with iodine colour won't change wash off with alcohol add safranin which stains it pink

Question 33

what are the functions of the cytoskeleton

Answer 33

allows movement of and around cells and maintains cell shape

Question 34

what are microfilaments

Answer 34

made of actin cell movement and contraction

Question 35

what are microtubules

Answer 35

made of tubulin determine cell shape and structure

Question 36

what are vesicles

Answer 36

move along microtubules by using motor proteins

Question 37

describe the process of protein synthesis and secretion

Answer 37

DNA is converted into mRNA by transcription mRNA leaves the nucleus through the nuclear pores mRNA is processed by the RER and attaches to a ribosome to become a protein by translation it leaves the RER in a vesicle it is modified in the golgi and leaves via another vesicle it fuses with the plasma membrane and leaves via exocytosis

Question 38

Eyepiece graticule calibration

Answer 38

Each division of the stage micrometer is 0.1 mm Each division of the graticule is on a scale from 0 to 100 See how many graticule divisions correspond to one stage micrometer division Divide by amount of graticule divisions to get what one EPGU equals

Question 39

How do you convert mm into micrometers

Answer 39

x1000