Biology assignment

JAIGANES A/L GUNALAN

MS2213104798

K1T03A

PN.KHAIRUL ANIDA BINTI BINTI OMAR

MOLECULES OF LIFE

STATE THE MAIN TYPE OF MOLECULES OF LIFE

DNA AND

PROTEIN MAIN TYPES OF RNA
MOLECULES IN MOLECULES

LIFE

LIPID

CARBOHYDRATES

WATER

Classify carbohydrates into three main classes based on their structure and

characteristic CARBOHYDRATES POLYSACCHARIDES

MONOSACCHARIDES DISACCHARIDES characteristic:
characteristic: characteristic: 1) Large/ macromolecules/
1) Sweet tasting 1) Sweet complex
2) Soluble in water 2) Not sweet
3) Can be crystallised 2) Water so
luble 3) Insoluble in water
4) Reducing agent 4) Cannot be crystallizsed
3) Can be crystallised
Structure:

a) straight-chain form, ring Structure:
form in aqueous
a) A double sugar molecule consist of
b) A sugar has :
- a carboxyl group (C=O) two monosaccharides
- many hydroxyl group
(-OH) b) Linked by glycosidic bond NEXT SLIDE

glycosidic bond is a covalent bond between two

monosaccharides by condensation reaction

1) STARCH 2) GLYCOGEN 3) CELLULOSE

-Polymers of alpha-glucose -Polymers of alpha-glucose -Polymers of beta-glucose
subunits
subunits subunits Structure:

Structure: Structure: beta-glucse monomers
linked
a) Amylose Similar to amylopectin long unbranched
the chains are
unbranched but extensively arranged in parallel
stick together through
only one type of linkage: alpha-branched formation of cross
linkages ( cross linkage
1,4 glycosidic bond 2 types of glycosidic is hydrogen bond
between the hydroxyl
amylose coils into helix linkage group of one cellulose
chain
b)Amylopectin - alpha 1-4 glycosidic

Branched chains every 30 linkage

units - alpha 1-6 glycosidic

have two types of linkages: linkage

- alpha-1,4 glycosidic bond

-alpha- 1,6 glycosidic bond

Structure of monosaccharides, disaccharides,
polysaccharides

1) Monosaccharides 2) Disaccharides 3) Polysaccharides

Humans are unable to digest vegetables, but herbivores are able to do so. Explain this
statement by focusing on a significant structure of the plant cell

Humans lack the enzyme necessary Animals such as cows have anaerobic
to digest cellulose. bacteria in their digestive tracts which
Vegetables are particularly digest cellulose.
abundant in cellulose, and both are Cows are ruminants. Ruminants have
indigestible by humans (although several stomachs that break down plant
humans can digest starch). materials with the help of enzymes and
Animals such as termites and bacteria.
herbivores such as cows, koalas and The partially digested material is then
horses all digest cellulose, but even regurgitated into the mouth, which is
these animals do not themselves then chewed to break the material down
have an enzyme that digests this even further.
material. The bacterial digestion of cellulose by
Instead, these animals harbour bacteria in the stomachs of ruminants is
microbes that can digest cellulose. anaerobic, meaning that the process does
not use oxygen.

Name the organelle which synthesizes carbohydrates in plant cells. Describe how the

organelle’s structure are involved in the synthesis of carbohydates

Chloroplast functions to synthesize monomers of carbohydrates in plant cell.
This occurs via the photosynthesis process which is carried out by plant cells.
The chloroplast is made up a bilayer membrane, a smooth outer membrane and a highly
folded inner membrane.
This increases surface area for the absorption of sunlight for the photosynthesis process to
occur and carbohydrates to be formed.
The chloroplast is made up of many disc- shaped entities known as thylakoid.
They house chlorophyll which are used to absorb sunlight to excite the electrons which is
then used to conduct phosphorylation of adenosine diphosphate to adenosine triphosphate
in photosynthesis.
It also gives the plant its green pigment.
The thylakoids are sometimes stacked as grana and are connected by a series of lamellae.
The grana are surrounded by a matrix substance known as stroma which contains dissolved
enzymes used for the and light independent reaction during photosynthesis.

THE END