cell ultrastructure

Question 1

nucleus structure

Answer 1

a membrane bound organelle containing nuclear pores, the nucleolus, and the nuclear envelope

Question 1

nucleus function

Answer 1

stores the genetic information of eukaryotic organisms using DNA. DNA directs the synthesis of all proteins therefore controls metabolic activity

Question 2

nucleolus function

Answer 2

produces ribosomes necessary for protein synthesis

Question 3

nuclear envelope function

Answer 3

a protective double membrane that contains the DNA, separating it from the cytoplasmic reactions to prevent damage

Question 4

rough endoplasmic reticulum function

Answer 4

manages the synthesis and transport of proteins

Question 5

RER structure

Answer 5

system of flattened sacs (cisternae) that arise near the nucleus and into the cytoplasm

Question 6

SER function

Answer 6

the production and storage of lipids

Question 7

golgi apparatus function

Answer 7

modifies and packages proteins into vesicles- either secretory vesicles or lysosomes

Question 8

golgi apparatus structure

Answer 8

cisternae (flattened membrane vesicles) and vesicles at each side

Question 9

mitochondria function

Answer 9

site of the conversion of stored energy into ATP in order for cellular respiration to occur

Question 10

mitochondria structure

Answer 10

double membrane bound, inner membrane forms a ‘cristae’ and the space within is the ‘matrix’

Question 11

lysosome function

Answer 11

a form of vesicle which stays in the cell, they contain hydrolyctic enzymes which break down a cell’s waste materials

Question 12

chloroplast function

Answer 12

responsible for photosynthesis- contains the green pigment chlorophyll which allows light-dependent reactions to occur

Question 13

plasma membrane function

Answer 13

protects the cell from it;s surrounding- stabilises the cytoskeleton. regulates transfer of cellular material

Question 14

centriole function

Answer 14

essential to the production of spindle fibres in cell division. constructed of microtubules

Question 15

cell wall function

Answer 15

made of cellulose for structural support, fully permeable so substances pass through freely- defence mechanism

Question 16

flagella function

Answer 16

tail-like extensions of a cell wall used to increase the mobility of cells

Question 17

cilia function

Answer 17

hair-like extensions of cells. can be stationary or mobile- used to help the transfer of liquids e.g mucus

Question 18

plasmodesmata function

Answer 18

facilitates the movement of molecules between cells in plants

Question 19

cytoskeleton function

Answer 19

consists of microfilaments, microtubules- provide strength to the cell. maintains the internal shape and organisation.

Question 20

capsule function

Answer 20

prokaryotic- protects the cell when engulfed by other organisms, retains moisture, adheres to surfaces

Question 21

plasmid function

Answer 21

prokaryotic- a small circular DNA molecule