Cell Structure

Question 1

define eukaryotic cell

Answer 1

cells with a nucleus and other double membrane bound organelles

Question 2

define ultrastructure

Answer 2

features that can be seen using an electron microscope

Question 3

draw a typical plant and animal cell

Answer 3

DRAW IT

Question 4

structure and function of the nucleus

Answer 4

structure:
contains DNA
nuclear envelope
nuclear pores

function:
DNA controls cell activities
RNA exported via nuclear pores
nuclear enveloped provides protection from cytoplasm

Question 5

structure and function of nucleolus

Answer 5

structure
made of proteins and ribosomes

function
produces ribosomes
makes rRNA which can then leave the nucleus

Question 6

structure and function of rough er

Answer 6

structure:
network of membranes enclosing cisternae
ribosomes bound to surface
connected to outer membrane of nucleus

function:
responsible for synthesis and transport of proteins

Question 7

structure and function of smooth er

Answer 7

structure:
network of membranes enclosing cisternae

function:
responsible for lipid and carbohydrate synthesis and storage

Question 8

structure and function of Golgi apparatus

Answer 8

structure:
compact structure formed by cisternae

function:
modify proteins
pack proteins into vesicles

Question 9

structure and function of mitochondria

Answer 9

structure:
double membrane
inner membrane folded to form cristae

functions:
cellular respiration

Question 10

structure and function of chloroplast

Answer 10

structure:
double membrane
internal membranes = thylakoids

function:
site of photosynthesis

Question 11

structure and function of centrioles

Answer 11

structure:
9 microtubule pairs

function:
involved in assembly of spindle fibres during cell division

Question 12

structure and function of flagella

Answer 12

structure:
extension from cell
made up of microtubule pairs

function:
propels cell
detect changes in cells environment

Question 13

structure and function ribosomes

Answer 13

structure:
not membrane bound
made of RNA
free floating or attached to ER

function:
site of protein synthesis

Question 14

structure and function of lysosomes

Answer 14

structure:
contain hydrolytic enzymes
specialised vesicle

function:
break down waste material
break down pathogens
role in apoptosis

Question 15

structure and function of plasma membrane

Answer 15

structure
double layer of phospholipids and proteins

function
partially permeable barrier
cell signalling

Question 16

structure and function of cell wall

Answer 16

structure:
cellulose
permeable

function:
provides structure
defence mechanism

Question 17

structure and function of cilia

Answer 17

structure:
made of microtubules
extensions off cell

function:
stationary - role in sense organs
mobile - beat rhythmically to move objects
eg mucus away from lungs, egg towards uterus

Question 18

3 similarities and differences between an animal and a plant cell

Answer 18

Similarities:
Cell surface membrane
nucleus
mitochondria
eukaryotes

differences:
plant has cell wall
plant has chloroplasts
animal has lysosomes

Question 19

draw and label a mitochondrion

draw and label a chloroplast

Answer 19

use book to check

Question 20

describe how organelles are involved in protein synthesis

• cell surface membrane
• mitochondria
• ribosomes
• nucleus
• RER
• vesicle
• exocytosis vesicle

Answer 20

cell surface membrane - partially permeable to allow amino acid in
mitochondria - produces ATP to provide energy for protein synthesis and movement of vesicles
ribosomes - proteins are synthesised and bound to RER
nucleus - DNA unwinds and a copy is made as RNA. RNA leaves nucleus and provides code for synthesising protein
RER - newly synthesised proteins pass into RER’s cisternae
vesicle - proteins packed in and vesicle transported to the Golgi apparatus
Golgi apparatus - modifies protein
vesicle - transports modified protein to cell surface membrane
- exocytosis vesicle fuses with cell membrane and releases contents

Question 21

name the 3 components of the cytoskeleton and describe their structure and function

• describe function of cytoskeleton

Answer 21

microfilaments:
structure - protein actin,
function: cell movement, contraction in cytokinesis

microtubules:
structure: polymer of protein tubulin
function: track for movement

intermediate fibres:
structure: protein
function: mechanical strength
maintain cells integrity

• cytoskeleton:
  gives shape and stability to cell
  holds organelles in place
  controls cell and organelle movement

Question 22

what is a prokaryotic cell

Answer 22

• a cell with no true nucleus and no membrane bound organelles

Question 23

examples of prokaryotic and eukaryotic cells

Answer 23

eukaryotic:
animal, plant, fungi

prokaryotic:
bacteria
archae

Question 24

draw and label a prokaryotic cell

Answer 24

DO ITTTTTT

Question 25

structure and function of cell wall in prokaryotes

Answer 25

structure:
muerin - polymer
function

Question 26

structure and function of ribosomes in prokaryotes

Answer 26

structure:
small - 70-80S
function:
involved in protein synthesis

Question 27

structure and function of bacterial flagellum in prokaryotes

Answer 27

structure:
small
have a molecular rotar for movement
attached to cell by basal body

function:
cell movement

Question 28

structure of plasmid prokaryotes

Answer 28

structure:

circular loop of DNA

Question 29

structure of bacterial chromosome in prokaryotes

Answer 29

• circular

- naked DNA

Question 30

function of pili in prokaryotes

Answer 30

involved in bacterial sex

helps bacteria attach to things

Question 31

function of slime capsule in prokaryotes

Answer 31

slime layer makes it sticky

Question 32

size of prokaryotic cell vs size of eukaryotic cell

Answer 32

prokaryotic: 0.1-10 um
eukaryotic: 10-100 um

Question 33

describe endosymbiotic theory

Answer 33

organelles eg chloroplasts and mitochondria were once prokaryotes. they have been taken into eukaryotes and now live in endosymbiosis