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Describe the process of DNA replication. - Correct Answer ✅💯DNA replication occurs in interphase
by *semi-conservative replication*.
*DNA helicase* is used *separate strands and break the hydrogen bonds* between both strands.
Both strands act as *template* and *free complementary nucleotides bind to the exposed bases* of
the template strands.
Complementary base pairing betwen adenine and thymine and guanine and cytosine.
*DNA polymerase* joins nucleotides and the *hydrogen bonds reform*.
Semi-conservative replication is finally done with new DNA molecules *containing one old strand
(template strand) and one new strand*
Describe the structure of a nucleotide - Correct Answer ✅💯Made up of a *pentose sugar, a
nitrogen-containing base and a phosphate group*.
Describe the structure of a water molecule? - Correct Answer ✅💯A water molecule is made up of
*two atoms of hydrogen and one of oxygen*
Water molecules are *dipolar* since hydrogen has a slightly positive side and the oxygen has a
slightly negative side. Therefore water molecules can form *hydrogen bonds* with each other.
Describe the structure of an amino acid. - Correct Answer ✅💯- *Amine Group (H2N)*
- *Carboxyl Group (COOH)*
- A *variable* carbon-containing group *(R)*
- A hydrogen (H)
Describe the structure of cellulose. - Correct Answer ✅💯Cellulose is a *long, straight, unbranched
chains of β glucose* molecules. Each chain is linked together by *hydrogen bonds* to form *strong
cross links* and *strong fibres known as microfibrils*.
Describe the structure of glycogen. - Correct Answer ✅💯Glycogen has a *large number of side
branches*, similar to amylopectin's structure.
Describe the structure of starch? - Correct Answer ✅💯Amylose is a *long, unbranched chain of α-
glucose* molecules. Due to its specific glycosidic bonding, its shape becomes *coiled*, which makes
it very *compact*.
, Amylopectin is a *long, branched chain of α-glucose* molecules. It has got many *side branches* on
it.
Describe the test for proteins? - Correct Answer ✅💯The test for proteins is known as the *biuret
test*
The steps are:
- *Add the test sample* to a test tube.
- Then add *sodium hydroxide solution*.
- Then add *copper(II) sulfate solution*.
- If the solution turns from *blue to purple*, then it indicates that *protein is present*
Explain the induced-fit model. - Correct Answer ✅💯The induced fit model proposes that when an
enzyme and a substrate interacts with each other, *a change is induced in the shape of the active
site*, moulding around the substrate molecule.
The change in shape of the active site *puts pressure/strain/stress* on certain bonds in the
substrate, *lowering the activation energy* required to break the bond.
Explain the relationship between the structure and function in glycogen. - Correct Answer ✅💯The
side branches in glycogen allow it to be *broken down much quicker* by enzymes, meaning that
energy can be *released quickly* as well.
Also, since it is highly branched, a *high amount of energy is released*. The energy released can be
used for important processes such as respiration.
Glycogen is also *insoluble* and therefore *do not affect the water potential*, so water cannot enter
cells by osmosis.
Explain the relationship between the structure and function in starch. - Correct Answer ✅💯The
coiled and compact shape of amylose allows a *lot of energy to be stored*, therefore making it good
for energy storage.
The side branches on amylopectin allow *enzymes to break down* the molecule and make it *easier
to break the glycosidic bond*. This means that energy can be *released quicker* for important
functions like *respiration*.
Starch is also *insoluble* and therefore *do not affect the water potential*, so water cannot enter
cells by osmosis.