L2 - cell types and subcellular structures

Question 1

what is the cell theory

Answer 1

1. all living organisms are made up of 1 or more cells
2. the cell is the basic unit of life
3. cells arise from existing cells by division

Question 2

what are prokaryotes and give examples

Answer 2

single celled organisms with no nucleus

bacteria / archaea

Question 3

what are eukaryotes and give examples

Answer 3

single or multicellular organisms that have nuclei 
animals 
plants 
fungi 
protozoans

Question 4

characteristics of prokaryotes

Answer 4

no nucleus - plasmid DNA sometimes
single celled
no membrane bound organelles

Question 5

what is the plasma membrane

Answer 5

phospholipid bilayer that surrounds cells and organnelles

Question 6

what can be found in the plasma membrane

Answer 6

cholesterol 
transmembrane proteins (receptors)

Question 7

roles of the plasma membrane

Answer 7

barrier
communication (receptors)
involved in import and export
enables electrical gradient

Question 8

what is the cytoskeleton - what are the 3 components

Answer 8

network of protein fibres

1. actin filaments
2. intermediate filaments
3. microtubules

Question 9

what are the main roles of the cytoskeleton

Answer 9

maintenance of shape and stability
involved in cell division
cell movement (as a whole)
movement of particles within cells

Question 10

what can be found in the cytoplasm

Answer 10

high [protein] eg. enzymes 
free ribosomes 
tRNA's 
water
inclusion bodies

Question 11

what are inclusion bodies

Answer 11

glycogen granules (energy store)

Question 12

describe the plasma membrane of the nucleus

Answer 12

two lipid layers (nuclear envelope) that contains pores

Question 13

what is the cytoplasm of the nucleus called

Answer 13

nucleoplasm

Question 14

what can be found in the nucleus

Answer 14

chromosomes (DNA)
packaging proteins (histones)
gene regulatory proteins
nucleolus

Question 15

what is the function of the nucleus

Answer 15

controls cellular processes

site of RNA synthesis and processing (splicing)

Question 16

what is the function of the nucleolus

Answer 16

site of ribosome synthesis

can capture regulatory proteins for further regulation

Question 17

what is the endoplasmic reticulum

Answer 17

network of interconnected membrane vesicles (cisternae)

Question 18

where is the Rough ER located?

Answer 18

continuous with outer nuclear membrane

Question 19

function of rough ER

Answer 19

protein synthesis (eg transmembrane proteins)

Question 20

what makes the RER rough?

Answer 20

ribosomes on the surface

Question 21

function of smooth ER

Answer 21

synthesis of lipids and steroid hormones

Question 22

what other functions does the SER have in cells of the liver

Answer 22

involved in:
detoxification
release of glucose from liver

Question 23

what is the golgi body

Answer 23

a stack of flattened membrane vesicles

Question 24

function of the golgi body

Answer 24

modification of proteins before secretion

Question 25

what is the order a protein will travel through organelles

Answer 25

RER - Cis gogli - Trans golgi - secretory vesicles

Question 26

describe the plasma membrane of mitochondria

Answer 26

double membrane

inner folded into cristae with a high content of transmembrane proteins

Question 27

functions of the mitochondria

Answer 27

metabolism & energy release
    krebs cycle
    oxidative phosphorylation 
produce heat 
store Ca2+
involved in apoptosis

Question 28

function of lysosomes

Answer 28

breakdown unwanted proteins/membranes/organelles/ particles

Question 29

what is the pH of lysosomes and why?

Answer 29

4.5-5

optimum pH for degradative enzymes

Question 30

function of peroxisomes

Answer 30

degrade FAs and toxic compounds by oxidation

produce precursors for many reactions

Question 31

what enzyme is found in peroxisomes and what is its function

Answer 31

catalase which neutralises any H2O2 produced in oxidation