BIOLOGY 1 (SB015)
ASSIGNMENT 2022/2023 SET B
BIO FLIPBOOK: 1.0 MOLECULES OF LIFE &
2.0 CELL STRUCTURES AND FUNCTIONS
NAME: MUHAMMAD FAHMI HAKIM BIN SHUKRI
MATRICS NO.: MS2113173479
i. State the main types of molecules of life (5 marks)
ii. Classify carbohydrates into three main classes based on their structure and
characteristic (15 marks)
iii. 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
iv. Name the organelle which synthesises carbohydrates in plant cells. Describe how
the organelles structures are involved in the synthesis of carbohydrates.
STATE THE MAIN TYPE OF MOLECULES OF LIFE
DNA & RNA
CLASSIFY CARBOHYDRATES INTO THREE MAIN CLASSES BASED ON THEIR STRUCTURE AND
Monosaccharides Disaccharides Polysaccharides
- Glucose - Sucrose - Starch
- Fructose - Maltose - Cellulose
-Galactose - Lactose - Glycogen
- Soluble in water
- Can be crystallised
- Reducing agent: Has free ketone
or aldehyde group, can donate electrons
to other molecules
It is a simple sugar within the carbohydrates classes which cannot be broken down into
smaller molecules by hydrolysis like the other carbohydrates classes. Monosaccharides has
a few characteristics which are sweet-tasting, soluble in water, can be crystallize, and
reducing agent; has a free ketone or aldehyde group, can donate electrons to other
molecules. It is monomers for disaccharides and polysaccharides and the general formula of
monosaccharide is (CH2O)n. n is the number of carbon atoms in the molecules.
- Water soluble
- Can be crystallized
Disaccharide is made from two monosaccharides through condensation reaction. One
water molecule is removed during condensation reaction. By condensation reaction,
covalent bond formed between two monosaccharides, the bond also known as glycosidic
linkage. There are a few characteristics for disaccharides such as sweet, water
soluble, and can be crystallized.
- Insoluble in water
- Cannot be crystallized
- Not sweet
Polysaccharides are polymers formed when hundreds of monosaccharides
joined by glycosidic linkages, it is formed through condensation reaction. The
chains formed may be variable in length, branched or unbranched, folded
which is ideal for energy storage, and straight or coiled. The characteristics for
polysaccharides are large or macromolecule or complex, not sweet, insoluble
in water, and cannot be crystallized.
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
The outermost layer of every plant cell is the cell wall, which is made from
fiber-like compounds like cellulose is a polysaccharides consists of many
β-glucose molecules that joined by β-1,4 glycosidic bond.
Cellulose can be broken down through hydrolysis catalysed by cellulose. In
general, humans can eat seeds, fruits, vegetables, roots, and many other
plant parts. With that said, our bodies aren't able to digest them all
completely because we, humans lack of cellulose.
Herbivores like cows, deer, and goats likewise cannot produce cellulase on
their own. However, they have friendly gut bacteria that produce it for them
while humans do not such gut bacteria to produce cellulase enzyme. The
gut bacteria help breaking down cellulose, thus digesting the vegetable in
gut of herbivore.
Name the organelle which synthesizes carbohydrates in plant cells. Describe how the organelle's structures are
involved in the synthesis of carbohydrates.
The organelle which synthesizes carbohydrates in plant cell is chloroplast.
chloroplast is an organelle in plant cell that function to carry out the
process of photosynthesis. photosynthesis is a complex series of reactions
carried out by chloroplast in algae, phytoplankton, and the leaves, which
utilize the energy from the sun.
Photosynthesis is a process where plant produce carbohydrate. In plant,
chloroplast has thylakoid that contain chlorophyll. Chlorophyll trap light
energy. And then enzymes in stroma will catalysed the synthesis of sugar and