Lesson-7-Cell-membrane-structure for G11

General biology senior high school general biology stem short for science technology engineering and mathematics

1. PHOSPHOLIPID BILAYER
Cell membrane structure

2. Define
phospholipid.
Explain the special
properties of
phospholipids.
Label and describe
the components of
a cell membrane.
LEARNING POINTS

3. WHAT ARE
PHOSPHOLIPIDS?
Phospholipids are the main
component in cell membranes.
They line up in a bilayer
arrangement, acting as a
barrier to water soluble
molecules.

4. The phospholipid tails
are two fatty acids.
The head of the
phospholipid is
made of one
molecule of
glycerol and a
phosphate
group.
PHOSPHOLIPID STRUCTURE

5. The fatty acid tails are non-polar
and hydrophobic (water hating).
They are insoluble in water.
The head is polar
because of the
phosphate group.
This makes the
head hydrophilic
(water loving).
It is soluble in
water.
PHOSPHOLIPID STRUCTURE
Phospholipids are amphipathic as they
have both hydrophilic and hydrophobic

6. CELL MEMBRANE
COMPONENTS
Cholesterol manages the fluidity of the
membrane and stops the phospholipids
sitting too closely together. This stabilizes
them and reduces the chance of the
membrane freezing in cold temperatures.
Cholesterol

7. CELL MEMBRANE
COMPONENTS
The carbohydrate chain on the
glycoprotein allows it to act as a receptor
molecule. They can bind with certain
substances and some act as cell markers
for cell-to-cell recognition.
Glycoprotein
Carbohydrate chain

8. CELL MEMBRANE
COMPONENTS
Glycolipid
Glycolipids stabilize the cell
membrane by making hydrogen bonds
with nearby water molecules. They
support with cell recognition and
triggering immune responses.

9. CELL MEMBRANE
COMPONENTS
Proteins create a passageway for ions and
polar molecules to move through the cell
membrane. Carrier proteins can transport
substances along or against the concentration
gradient by changing conformation and binding
to substances.
Carrier Protein

10. CELL MEMBRANE
COMPONENTS
Channel protein
Channel proteins transport ions and
polar molecules along the
concentration gradient. The pores
allow substances to pass through
without binding to the protein.