UNIT TWO - Cells - Cell structure

Question 1

Define eukaryotic cell

Answer 1

cell that contains a membrane bound nucleus

Question 2

define a prokaryotic cell

Answer 2

cell that doesn’t contain a nucleus

Question 3

name examples are eukaryotes

Answer 3

plants
animals
fungi
protists

Question 4

Describe the function of a nucleus

Answer 4

contains the genetic material in the form of chromatin which is made of DNA and histone proteins

Question 5

Describe the function of ribosomes

Answer 5

to carry out protein synthesis

Question 6

Describe the function of a rough endoplasmic reticulum

Answer 6

contains ribosomes on its outer surface which synthesis proteins . It the transports proteins through the cell

Question 7

Describe the function of a smooth endoplasmic reticulum

Answer 7

synthesizes and transports lipids

Question 8

Describe the function of a golgi apparatus

Answer 8

modifies and packages proteins from the RER into vesicles for secretion

Question 9

Describe the function of lysosomes

Answer 9

these are vesicles containing lysozymes which are digestive enzymes which cause hydrolysis eg - of invading pathogens or worn out organelles

Question 10

Describe the function of mitochondria

Answer 10

carry out aerobic respiration and produce ATP

Question 11

Describe the function of a cell surface membrane

Answer 11

controls movements of substances into and out of cell

Question 12

Describe the function of a chloroplast

Answer 12

The site of photosynthesis

Question 13

Describe the function of a cell wall

Answer 13

gives cells support and prevents them from bursting

Question 14

Describe the function of a cell vacuole

Answer 14

helps to maintain pressure inside the cell and keep the cell rigid

Question 15

Describe the structure of a nucleus

Answer 15

It has a double membrane with pores that allows substances to move between the nucleus and cytoplasm

Question 16

Describe the structure of ribosomes

Answer 16

made of proteins and rRNA
consists of a small sub unit and a large sub unit
float free in cytoplasm or are attached to the rough endlplasmic reticulum
Eukaryotes contain 80s ribosomes

Question 17

Describe the structure of the rough endoplasmic reticulum

Answer 17

made of flattened membrane sac called cisternae

Question 18

Describe the structure of the smooth endoplasmic reticulum

Answer 18

made of flattened membrane sac called cisternae

Question 19

Describe the structure of mitochondria

Answer 19

have a double membrane
the inner membrane is folded to form cristae (singular = crista)
They have their own DNA and ribosomes
They have a matrix which contains DNA, ribosomes and enzymes for aerobic respiration

Question 20

Describe the structure of a cell wall

Answer 20

Made of cellulose in plants and aglae

Made of chitin in fungi

Question 21

Describe the structure of a cell vacuole

Answer 21

contains cell sap and has a surrounding membrane called the tonoplast

Question 22

Name the features of a chloroplasts’ structure

Answer 22

Granum 
thylakoid membrane
stroma
starch grains
DNA and ribosomes

Question 23

Define the granum of a chloroplast

Answer 23

a stack of thylakoid membranes - increases the surface area for absorption of sun light

Question 24

Define the thylakoid membrane of a chloroplast

Answer 24

contains chlorophyll for photosynthesis - increases the surface area for absorption of sun light

Question 25

Define the stroma of a chloroplast

Answer 25

fluid filled matrix that contains enzymes for some of the photosynthetic reactions

Question 26

Define the starch grains of a chloroplast

Answer 26

the storage molecule in plants - a polysaccharide that doesn't effect the water potential of the cell

Question 27

Define the DNA and ribosomes of a chloroplast

Answer 27

chloroplasts have their own to make enzymes needed for photosynthesis

Question 28

In terms of cells and cell structure , describe the process of producing and secreting proteins

Answer 28

1. DNA in the cell's nucleus is what codes for proteins 2. mRNA leaves the nucleus 3. protein synthesis occurs at the ribosomes and the mitochondria produces ATP for this reaction 4. Rough endoplasmic reticulum transports protein from ribosomes to golgi apparatus 5. golgi apparatus modifies and packages protein into vesicle 6. vesicles transport proteins to the cell surface membrane and fuse with the cell surface membrane

Question 29

List the organelles that all prokaryotic cells have

Answer 29

``` cytoplasm ribosomes cell surface membrane cell wall free DNA ```

Question 30

List the organelles that some prokaryotic cells have

Answer 30

capsule plasmids flagellum

Question 31

Describe a prokaryotic cell wall

Answer 31

made of murein - a glycoprotein

Question 32

Describe a plasmid

Answer 32

circular piece of DNA seperate from the main loop of DNA

Question 33

What to prokaryotes have instead of a nucleus

Answer 33

single, circular piece of DNA that is free in the cytoplasm and coiled up

Question 34

What is a flagellum

Answer 34

long hair like structure that aids movement of some prokaryotes

Question 35

How is prokaryotic DNA different to eukaryotic DNA

Answer 35

prokaryotic DNA is ... . ``` shorter with fewer chains doesn't contain introns floats free in the cytoplasm its circular as opposed to linear its not associated with histone proteins only one piece of DNA or present as plasmids ```