T2 - WHY ARE CELLS ORGANISED INTO COMPARTMENTS

Question 1

endosymbiosis

Answer 1

symbiotic cell theory
archaea engulfed bacteria similar to mitochondria

• beneficial as this bacteria got resources from archaea and the archaea got the respiratory/energy products

Question 2

theory of symbiosis

Answer 2

theory suggests that bacteria aerobically respires/gives benefit to archaea cells
- archaea cell respires anaerobically and can provide protection to the bacteria
-
- archaea engulfed the bacteria and overtime a relationship developed and became interconnected such that the bacteria could not survive without the archaea forming eukaryotic cell

Question 3

primary and secondary symbiosis

Answer 3

primary symbiosis is the first time endosymbiosis happens with a cell, eg the archaea and aerobic bacteria

secondary is the 2nd time
eg a photosynthetic bacteria engulfed into a cell which has already undergone symbiosis with the aerobic bacteria

Question 4

mitochondria and chloroplasts

Answer 4

-contain own DNA
- proliferate by division
- surrounded by a double membrane (inner is original membrane from bacteria and outer membrane is what formed when engulfed)

Question 5

why is compartmentalisation in cells so important?

Answer 5

it allows cells to be big and complex, separating the environments so different metabolic reactions can occur with greater efficiency

• the compartments will have a greater concentration of substrates necessary for their specific reaction, increasing the rate of reaction for that process

Question 6

microvilli

Answer 6

membrane projections that increase the cells surface area

Question 7

plasmodesmata

Answer 7

cytoplasmic channels through cell walls that connect the cytoplasm of adjacent cells

Question 8

peroxisome

Answer 8

organelle with various specialised metabolic functions, produces hydrogen peroxide as a by-product and then converts that into water

Question 9

lysosome

Answer 9

digestive organelle where macromolecules are hydrolysed by lysozyme

Question 10

nucleolus

Answer 10

nonmembranous structure involved in production of ribosomes; a nucleus has one or more nucleoli

Question 11

chloroplast

Answer 11

photosynthetic organelle; converts light energy to chemical energy stored in sugar molecules

Question 12

centrosome

Answer 12

region where the cells microtubules are initiated,contains a pair of centrioles

Question 13

chromatin

Answer 13

material consisting of DNA and proteins;visible in a dividing cell as individual condensed chromosomes

Question 14

golgi apparatus

Answer 14

organelle active in synthesis, modification,sorting and secretion of cell products

Question 15

nuclear envelope

Answer 15

double membrane enclosing the nucleus, perforated by pores and a continous ER

Question 16

flagellum

Answer 16

motility structure present on some animal cells, composed of a cluster of microtubules within an extension of plasma membrane

Question 17

endoplasmic reticulum

Answer 17

network of membraneous sacs and tubes, active in membrane synthesis and other synthetic and metabolic processes, has a smooth and rough region

Question 18

ribosomes

Answer 18

complexes that make proteins, free in cytosol or bound to rough ER or nuclear envelope

Question 19

central vacuole

Answer 19

organelle in older plant cells,functions include storage, breakdown of waster products,hydrolysis of macromolecules, enlargement of vacuole in a major mechanism of plant growth

Question 20

cell wall

Answer 20

outer layer that maintains cells shape and protects cell from mechanical damage, made out of cellulose, other polysaccharides and proteins

Question 21

mitochondria

Answer 21

organelle where cellular aerobic respiration occurs, generating ATP

Question 22

cytoskeleton

Answer 22

reinforces cells shape, functions in cell movement, components are made of proteins including microfilaments, intermediate filaments and microtubules