3.2.1 | cells

Question 1

what is the structure of eukaryotic cells?

Answer 1

can be uni or multicellular, have membrane bound organelles and 80s ribosomes

Question 2

what is the DNA in eukaryotic cells?

Answer 2

linear DNA in the nucleus, wrapped around histones to form chromatin which are coiled into chromosomes,

Question 3

what is the structure of the cell membrane?

Answer 3

a phospholipid bilayer with molecules embedded inside it

Question 4

what are the 2 functions of the cell membrane?

Answer 4

regulates movement of substances in and out of cells
has receptors on the surface that respond to chemicals like hormones

Question 5

what is the structure of the RER and SER?

Answer 5

sheets of membranes enclosed in a fluid filled space
forms flattened sacs called cisternae
RER has ribosomes on surface

Question 6

what are the 2 functions of the RER?

Answer 6

site of proteins synthesis on ribosomes
proteins in lumen of RER fold into tertiary structure and are then packed into vesicles and transported to golgi

Question 7

what is the function of the SER?

Answer 7

synthesis and storage of lipids and carbohydrates

Question 8

what is the structure of the golgi apparatus?

Answer 8

system of membrane enclosing a fluid filled space, folded into cisternae

Question 9

what are the 3 functions of the golgi apparatus?

Answer 9

processes and packages proteins
packs proteins into vesicles
makes vesicles and lysosomes

Question 10

what is the structure of golgi vesicles?

Answer 10

small, fluid filled, membrane sacs that are found at edges of apparatus

Question 11

what are the 3 functions of golgi vesicles?

Answer 11

transports lipids and proteins made my golgi body
fuses with cell membrane
releases contents by exocytosis

Question 12

what is the structure of lysosomes?

Answer 12

membrane bound sacs filled with hydrolytic enzymes called lysozymes

Question 13

what are the 4 functions of lysosomes?

Answer 13

digest large molecules into smaller ones
involved in phagocytosis
digest old organelles in cells
digests invading cells

Question 14

what is the structure of ribsomes?

Answer 14

made of 2 subunits, proteins and RNA

Question 15

what is the function of ribosomes?

Answer 15

site of protein synthesis

Question 16

what is the structure of mitochondria?

Answer 16

double membrane with an intermembrane space, inner membrane form crista, matric inside the inner membrane

Question 17

what is the function of mitochondria?

Answer 17

site of aerobic respiration to produce ATP

Question 18

what is the structure of chloroplast?

Answer 18

have a double membrane, have thylakoids stacked to make a grana, has fluid called stroma

Question 19

what are the 3 functions of the chloroplast?

Answer 19

site of photosynthesis
light-dependant stage in thylakoid
light independent stage in stroma which contains enzymes for it

Question 20

what is the structure of different cell walls?

Answer 20

plants and algae contain cellulose
fungi contain chitin
bacteria contain murein, peptidoglycan and glycoprotein

Question 21

what are the 4 functions of the cell wall?

Answer 21

keeps cell shape
supports and strengthens cells
strong enough to resist hydrostatic pressure
permeable to water molecules

Question 22

what is the structure of vacuoles?

Answer 22

a membrane sac that is filled with fluid called tonoplast and cell sap

Question 23

what are the 4 functions of vacuoles?

Answer 23

maintains pressure inside cell
keeps cell rigid
stops plant wilting
when water enters, becomes turgid

Question 24

what is cell specialisation?

Answer 24

the way cells adapt for their specific function to make it efficient

Question 25

what are 3 examples for specialisation?

Answer 25

muscle cells have lots of mitochondria so release lots of ATP for contractions sperm cells have lots of mitochondria + tails so lots of ATP released for swimming towards egg white blood cells have lots of lysosomes for phagocytosis and digestion

Question 26

what is the structure of prokaryotic cells?

Answer 26

single-celled organisms, have no membrane-bound organelles, 70s ribosomes, cell walls made of murein

Question 27

what is the DNA of prokaryotic cells?

Answer 27

free-floating in the nucleus, circular DNA and have plasmids which are single loops which have gene for antibiotic resistance

Question 28

what are the organelles in prokaryotic cells?

Answer 28

plasmids, proteins, ribosomes, cytoplasm, storage granules, cell envelope, capsule, pilli and flagella

Question 29

what is a capsule?

Answer 29

layer of protein that protects bacterial cells from phagocytosis

Question 30

what is flagella?

Answer 30

long appendages that aid motility

Question 31

what is the structure of a virus?

Answer 31

acellular, not alive, capsid, attachment proteins, viral envelope, RNA strand

Question 32

what is magnification?

Answer 32

how much bigger the image is than the specimen

Question 33

what is resolution?

Answer 33

the minimum distance apart 2 objects are that they appear as separate objects

Question 34

what are artefacts?

Answer 34

anything seen in a microscopic image that isn't apart of the specimen

Question 35

what is the equation to calculate magnification?

Answer 35

magnification= image size/ actual size

Question 36

what are the stages of interphase?

Answer 36

G0, G1, S phase, G2

Question 37

what are the 5 stages of mitosis?

Answer 37

interphase, prophase, metaphase, anaphase and telophase

Question 38

what step takes place after mitosis?

Answer 38

cytokinesis

Question 39

what happens during gap phase 0?

Answer 39

cell is resting and not dividing

Question 40

what happens during interphase?

Answer 40

cell grows, DNA replication, organelle replication

Question 41

what happens during prophase?

Answer 41

chromosomes condense and become visible, are x shaped sister chromatids joined at centre by a centromere, spindle fibres form across the cell

Question 42

what happens during metaphase?

Answer 42

spindle fibres attach at centromere and line chromosomes in centre of the cell,

Question 43

what happens during anaphase?

Answer 43

spindle fibres pull sister-chromatids to opposite poles of the cell

Question 44

what happens during telophase?

Answer 44

new nuclear envelope forms around 2 full sets of chromosomes, forms genetically identical daughter nuclei

Question 45

what happens during cytokinesis?

Answer 45

cytoplasm splits into 2 genetically identical daughter cells

Question 46

what is cancer?

Answer 46

uncontrolled cell division

Question 47

what is a mutation?

Answer 47

a change in the base sequence of DNA

Question 48

how does cancer treatments work?

Answer 48

disrupts the cell cycle of healthy and cancer cells

Question 49

where are the checkpoints during the cell cycle?

Answer 49

G1, S, G2, metaphase

Question 50

what happens during the G1 checkpoint?

Answer 50

checks if cell is big enough

Question 51

what happens during the S checkpoint?

Answer 51

checks if DNA replicated correctly

Question 52

what happens during G2 checkpoint?

Answer 52

checks if replication correct and cell big enough to undergo mitosis

Question 53

what happens during metaphase checkpoint?

Answer 53

makes sure spindle fibres attached correctly

Question 54

what happens during binary fission?

Answer 54

circular DNA and plasmids replicate cell gets bigger and DNA moves to opposite ends of cell cytoplasm begins to divide cytoplasm fully splits into two daughter cells

Question 55

what happens during viral replication?

Answer 55

virus attaches to host cell using attachment proteins viral genetic material is released into host uses host to replicate genetic material and proteins viral components assemble inside host cell and replicated viruses leave host cell