eukaryotic cell structure

Question 1

list organelles in eukaryotic animal cells

Answer 1

• cell membrane
• nucleus
• RER
• SER
• mitochondria
• lysosome
• golgi body
• vesicle
• centriole

Question 2

structures in cell membrane

Answer 2

• phospholipid bilayer
• proteins
• cholesterol

Question 3

function of cell membrane

Answer 3

• contains organelles
• selectively permeable to control entry and exit of materials
• protects cell from harmful chemicals
• takes part in metabolic processes

Question 4

structures in nucleus

Answer 4

• chromosomes
• nucleoplasm
• nucleolus
• nuclear pores
• nuclear envelope

Question 5

function of nucleus

Answer 5

• synthesis of ribosomes and RNA
• control centre for cell
• retaining genetic material in form of DNA and chromosomes consisting of protein-bound, linear DNA

Question 6

function of nuclear pores

Answer 6

allows passage of large molecules such as messenger RNA

Question 7

function of nuclear envelope

Answer 7

• controls entry and exit of materials

- contains reaction

Question 8

function of nucleolus

Answer 8

• site of ribosome synthesis

Question 9

size of nucleus

Answer 9

10-20 um in diameter

Question 10

structures in mitochondria

Answer 10

• double membrane
• cristae
• matrix

Question 11

function of mitochondria

Answer 11

• site of aerobic respiration (Krebs cycle/ oxidative phosphorylation pathway)
• production of ATP

Question 12

function of matrix

Answer 12

contains proteins, ribosomes, DNA and enzymes

Question 13

function of cristae

Answer 13

• extensions of inner membrane provide large surface area for enzymes and proteins in respiration

Question 14

which type of cells contain high numbers of mitochondria?

Answer 14

cells involved in metabolic processes requiring lots of ATP

• muscle cells
• epithelial cells (absorbing substances from intestine by active transport)

Question 15

what does ATP stand for and what is it?

Answer 15

• adenosine triphosphate

- nucleotide produced during respiration - transfer of energy

Question 16

size/shape of mitochondria

Answer 16

1-10 um in length

rod-shaped

Question 17

structures of golgi apparatus

Answer 17

• stacks of membranes forming cisternae with vesicles

Question 18

function of golgi apparatus

Answer 18

• secretes carbs
• add carbs to proteins forming glycoproteins
• produces secretory enzymes
• transports lipids
• forms lysosomes

Question 19

describe the strict sequence of lipids/proteins produced by ER passed through the golgi body

Answer 19

• modifies lipids by adding carbs
• labels them so they go to correct destination
• transported in vesicles which are pinched off the ends of the cisternae
• vesicles move to cell surface to fuse with membrane and release contents

Question 20

in what type of cells is the golgi body well developed?

Answer 20

secretory cells such as epithelial cells lining intestine

Question 21

what is a lysosome?

Answer 21

type of golgi vesicle releasing lysozymes (+ hydrolytic enzymes)

Question 22

functions of a lysosome

Answer 22

• hydrolyse materials ingested by phagocytic cells
• release enzymes outside of cell to destroy materials around it (exocytosis)
• digest worn out organelles for reuse
• break down dead cells (autolysis)

Question 23

structure of a ribosome

Answer 23

• small cytoplasmic granule (also found in RER)

- consists of a large and small subunuits

Question 24

what are the two types of ribosomes?

Answer 24

80S -eukaryotic cells (25nm)

70S - prokaryotic cells, mitochondria and chloroplast (smaller)

Question 25

function of ribosomes

Answer 25

protein synthesis

Question 26

structure of RER (rough endoplasmic reticulum)

Answer 26

extensive network of membranes enclosing tubules and cisternae - continuous with the nuclear membrane

Question 27

functions of RER

Answer 27

- provide large SA for protein/glycoprotein synthesis | - pathway for transport of materials (proteins) throughout cell

Question 28

structure of SER (smooth endoplasmic reticulum)

Answer 28

- no ribosomes on surface (smooth) | - more tubular in appearance

Question 29

functions of SER

Answer 29

- synthesis, store and transport lipids | - synthesis, store and transport carbohydrates

Question 30

list extra organelles in eukaryotic plant cells

Answer 30

- cell wall - chloroplasts - vacuole

Question 31

structures of cell wall

Answer 31

- microfibrils of cellulose in a matrix and a thin layer called middle lamella

Question 32

functions of cell wall

Answer 32

- provide mechanical strength for plant as a whole - provide mechanical strength to prevent cell bursting due to osmosis - controls movement of water

Question 33

what is the cell wall of fungi made of?

Answer 33

polysaccharide - chitin (glycan +glycoproteins)

Question 34

what is the cell wall of algae made of?

Answer 34

cellulose or glycoprotein or both

Question 35

structure of vacuole

Answer 35

- fluid-filled sac bounded by single membrane (tonoplast) | - contains solution of mineral salts, sugars, amino acids, wastes and pigments (e.g. anthocyanin)

Question 36

functions of vacuole

Answer 36

- support plants by making them turgid - act as temporary food store (sugars/amino acids) - pigments colour petals to attract pollinating insects

Question 37

structures of chloroplasts

Answer 37

- chloroplast envelope - grana - stroma

Question 38

function of chloroplast

Answer 38

carry out photosynthesis

Question 39

function of chloroplast envelope

Answer 39

double plasma membrane which is selectively permeable to control entry and exit of materials

Question 40

function/structure of grana

Answer 40

1st stage of photosynthesis (light absorption) | - stacks of thylakoids containing chlorophyll

Question 41

function/structure of stroma

Answer 41

2nd stage of photosynthesis (synthesis of sugars) | - fluid-filled matrix containing other structures such as starch grains

Question 42

how are chloroplasts adapted to their function for photosynthesis?

Answer 42

- granal membrane: large SA for attachment of chemicals which carry out 1st stage of photosynthesis (chlorophyll/ electron carriers/ enzymes - stroma fluid - contains enzymes for synthesis of sugars in 2nd stage of photosynthesis - DNA/ribosomes - manufacture proteins needed for photosynthesis