SET C MS2113173272 NUR ALIN NATASHA H8T03B

EROBIOLOGY FLIPBOOK
T EN A
GRE
SMOLECULES GOF LIFE &

STRUCTURE ANODU RFUNCTION

NAME:NUR ADLIN NATASHA BT
AHMAD NIDZAM
MATRICS NO : MS2113173272
PRACTICUM : H8P03B
LECTURER NAME : MADAM PUTERI
BALQIS BT MOHD ISHLI

SET C

main types of molecules of life

WATER NUCLEIC ACID

PROTEIN

LIPIDS CARBOHYDRATES

classify lipids

Lipids are classified into 3 types which
are TRIGLYCERIDES , PHOSPHOLIPIDS
and STEROIDS .

TRIGLYCERIDES

Triglycerides is a type of fat ( lipid ) can be found in
our body . Triglycerides can be form into liquid and
fat which is solid and liquid at room temperature .

Triglyceride molecules consists of a glycerol
backbone esterified with three fatty acids . Glycerol

is type of alcohol contain 3 carbon atoms and 3
hydroxyl groups . Fatty acid consists of a long linear
hydrocarbon chain and a carboxyl group . Fatty acids

joins to glycerol by condensation . Although, it is
similar in structure to the phospholipids that build

cell membranes , triglycerides are completely
hydrophobic meaning they cannot mix with water , so

the cannot integrate into membranes. .

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PHOSPHOLIPIDS

Phospolipids are compound lipids , consisting of phosphoric acid , nitrogen base ,
alcohol and fatty acid . It is made up of a phosphate group , two alcohols and one or two
fatty acids .These compound lipid are major component of the cell membranes and also

provide a fluid character to the membrane . Phospholipid are made up of two
hydrophobic tails of fatty acids and one hydrophillic head , jointed together by alcohol
or glycerol . Due to this structure arrangement , phospholipids form lipid bilayer and

are a key compenent of all cell membranes . This bilayer is held together by weak
hydrophobic interaction between tails .

STEROIDS

Steroid is a biologically active organic
compound with four fused carbon ring

arranged in a specific molecules .
Steroids has two principal biological
function which alter the membrane
fluidity and as signaling molecules .
Steroid molecules structure composed
of 17 carbon atom - arranged in four ring
conventionally denoted by the letter A ,

B , C and D which bonded to 28
hydrogens atom .

Plasma Membrane

described by the Fluid Mosaic Model which are proposed by S.J Singer & G.L Nicolson
(1972)

Membrane is composed of 2 layer ( bilayer ) of phopholipids with globular proteins embedded in
the bilayer

FLUID : phopholipid & protein can move latererally
Accounted for the amphipathic characteristic of phospholipid & protin

have both hydrophobic regions & hydrophillic regions

PHOSPHOLIPIDS PROTEIN

the hydrophilic head face watery environment 2 type of protein :

the hydrophobic tail hide away from water - integral
- peripheral

form an excellent lipid bilayer cell membrane integral - partially embedde or fully

that separates fluid within the cell from the fluid embedded

outside of the ce - transmembrane protein

help cell membranes and membranes surrounding peripheral - attached to the outer
organelles to be flexible and not stiff.
& inner surfaces of the membrane

CHOLESTEROL CARBOHYDRATE

found between phospholipid CHAIN
reducing the permeability of the cell membrane.
is cell-to-cell recognition

on the outer surface of the

plasma membrane and are

attached to proteins,

forming glycoproteins, or

lipids, forming glycolipids.

Lipids ensure fluidity

Factors that effect the lipid fluidity is cholesterol . Function of Cholesterol
is to increase flexibility & stabilizes the membrane structure by regulating the fluidity
of membrane . At the moderately warm temperatures , cholesterol reduce membrane
fluidity by preventing free movement of phopholipids molecules . At cool temperatures ,
cholesterol prevent close packing of phopholipids & slow down solidification . Then

membrane fluidity also regulate phospolipid and cholesterol .Phospholipid has
hydrophillic heads facing outwards and attracted to the aqueous surrounding and
hydrophobic tails facing inwards . Phospholipid also can move side by side , their are

dynamic and can provide fluiduty by plasma membrane.