Cell Structure
Some quick revision…
nucleus
cytoplasm
cell membrane
We will be spending 2 weeks looking at
the contents of the cytoplasm
Cell Structure
The cytoplasm is not a
featureless soup.
It is a matrix full of structures
(organelles).
Each organelle has a specific
structure and function
Cell Structure
MN
•Nucleus
•Nucleolus
•Centriole
•Ribosomes
HT
•Smooth/rough ER
•Golgi apparatus
• Mitochondria
•Lysosomes
•Chloroplasts
•Plasma membrane
•Cilia
This Weeks Objectives:
Describe the
structure &
function of……
•Smooth/rough ER
•Golgi apparatus
• Mitochondria
•Lysosomes
•Chloroplasts
•Plasma membrane
•Cilia
Endoplasmic Reticulum (ER)
Definition:
• A system of membranes found
in both animal and plant cells
•They can with the nucleus or
be detached.
•They can with lined with ribosomes
Rough ER or Smooth ER?
Most of the ER is encrusted with
small granules called ribosomes –
this is the rough ER.
The smooth ER does not have any
ribosomes
FUNCTIONS OF ER:
Synthesis & transport
Rough ER
of proteins
Synthesis
&
transport
Smooth ER
of lipids & steriods
The Golgi Apparatus
Definition:
• A system of membranes and
folded vessicles found in both
animal and plant cells
• Involved in storage and transport of
products that are secreted from the cell.
• e.g. hormones and enzymes
The Golgi Apparatus
Lots of substances that leave the cell are
GLYCOPROTEINS
GLYCOPROTEINS are a mix of
carbohydrate and protein
Where are proteins synthesised?
Rough Endoplasmic Reticulum (RER)
So the Golgi Apparatus must be closely
associated with the RER!
The Mitochondria
What do you already know?
An organelle
Produces E
for the cell
What do you need to know?
The Mitochondria
Task: You have 5 minutes to
find 10 characteristics of
mitochondria
Sausage shaped
Ave. 1000 per cell
Have an inner & outer membrane
Inner membrane is highly folded,
Producing fingers called CRISTAE
Fluid filled internal area - matrix
It is the site of respiration
ATP is produced here
The cristae are folded to increase the
surface area
increased respiration
More E cell need = more mitochondria rqd.
Sperm tails
Wings of insects
Mammalian muscle fibres
Lysosomes
Definition:
A membrane bound sac found in
A&P cells
Contain digestive enzymes
WHY?
Digestive enzymes break up:
bacteria
old organelles
foreign bodies
How?
Task: 5 minutes to get the
order correct on the next slide!
Lysosomes fuses with membrane around
unwanted structures
Old/wanted structures break down
Cell reabsorbs products back into
cytoplasm
Membrane surrounds old/unwanted
structures
Lysosome releases digestive enzymes
into membrane
Membrane surrounds old/unwanted
structures
Lysosomes fuses with membrane around
unwanted structures
Lysosome releases digestive enzymes
into membrane
Old/wanted structures break down
Cell reabsorbs products back into
cytoplasm
Chloroplasts: What do you know?
Contain chlorophyll
Plants only
Site of P
Green
What else you need to know!