Intro to cell structure and function

Question 1

Organelle

Answer 1

cell components that perform specific functions and are surrounded by own membrane

Question 2

what does the nucleus contain and control

Answer 2

contains genetic info
controls activities of the cell

Question 3

features of the nucleus

Answer 3

1. contains the genome
2. nuclear envelope with pores to allow export of mRNA
3. nucleolus
4. shape maintained by protein skeleton ‘nuclear matrix’

Question 4

nucleolus function

Answer 4

involved in production of ribosomal RNA to form ribosomes

Question 5

what do the nuclear pores do

Answer 5

ctrl passage of macromolecules into the nucleus

Question 6

RER appearance and function

Answer 6

• studded with ribosomes to be exported from the cell
• intracellular highway for molecules movement and modification

Question 7

SER function

Answer 7

for specialised metabolism and storage

Question 8

Endoplasmic reticulum features

Answer 8

1. highly folded membrane system continuous with outer nuclear envelope- has inner lumen
2. Proteins chemically modified within ER provides correct enviro
3. SER has few ribosomes but instead has embedded transmembrane enzymes that processes lipids
4. main site od new membrane synthesis in cell
5. hides calcium within lumen

Question 9

Golgi features

Answer 9

system of membrane sacs piled on top of each other
- near cell centre= cis / far= trans
- proteins are modified within the golgi, passes through layers of cisternae by budding and fusing with next layer
- materials packaged into membrane enclosed vesicles which pinch off from edges

Question 10

what are lysosomes and endosomes

Answer 10

inter-related single membrane bound compartments in cell

Question 11

lysosomes features

Answer 11

• vesicles containing digestive enzymes produced from ER and mature to form lysosome
• lysosome contains digestive enzymes and are “suicide bags”

Question 12

endosomes features

Answer 12

-transports substances through the cell by engulfing them and spitting them out in vesicles

Question 13

mitochondrion features

Answer 13

• two membranes, latter has extensive ‘cristae’ to increase SA
  -more plentiful in cells with high energy requirements
• inner membrane embedded with metabolic proteins
• mitochondria have own genomic DNA

Question 14

what is the most common plastid

Answer 14

chloroplast

Question 15

plastid features

Answer 15

double membranes at border- inner space “stroma” with membrane sacks “thylakoids” arranged in coin like stacks called ‘grana’
- genomic DNA
- protein photoreceptors on thylakoid membrane are site of photosynthesis and ATP production

Question 16

vacuole features

Answer 16

• fluid filled membrane bound sacs
• prominent structure in planst cells, up to 90% of space
• serves as storage area and contains water and chemicals
• bounded by tonoplast membrane with protein pumps which transport molecules into the vacuole
  -plant cells provide high turgor pressure for cell strength

Question 17

ribosomes

Answer 17

-small dense staining granules
- very numerous
-sites of protein synthesis

Question 18

centrioles

Answer 18

• found in animal cells
• found either side of nucleus during nuclear division
• create spindle apparatus during cell division

Question 19

cytoskeleton

Answer 19

• composed of proteinaceous microtubules
• provides cell framework and motility