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What is a genome?
A genome is all the genetic material contained in the chromosomes of an organisms.
Dna carries our genetic code and contains the instructions for making proteins via our genes.
Proteins have several different vital uses in our body, but one of the most important is the control
of cellular functions.
What are proteins?
Proteins are big molecules ­they are natural polymers. They play a key role in almost every
structure and activity of a living organism.…read more

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-Reactions of amino acid 13.9
Proteins are replaced in all of us continuously in all of us. It is important when hormones and
enzymes are made when they are needed and destroyed once their jobs are done
-proteins are replaced from the food we eat, we don't even need animal protein we can get the
supply from plants
-our body breaks down proteins into constituent `building blocks' ­ amino acids.…read more

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Tertiary structure the chains are folded up further and stabilised by bonds that occur between the r group
of the amino acids in the chain.
Instantaneous dipole ­ induced dipole bonds between the nonpolar side chains on amino acids
such as phenylalanine and leucine. The centre of the protein molecules tend to contain amino
acids like these, so the nonpolar groups do on interfere with the hydrogen bonding between the
surrounding water molecules.…read more

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it.This region is called the active site.
The bonds that bind the substrate to the active site have to be weak so the binding can be readily
reversed when the products need to leave the active site after the reaction. The bonds are usually
hydrogen bonds or interactions between ionic groups.…read more

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Activation enthalpy in chemical ideas 10.1 and 10.2,catalysts chemical ideas 10.5 and 10.6
Factors that affect the performance of the enzymes
-if an enzymes active site contains ionisable groups the enzymes actions will be affected by a
change in Ph. Eg. If there is a ­COOhgroup that acts by donating an H+ to an substrate, raising the
ph will turn it into ­COO- and the enzymes will not be able to function correctly.…read more

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One of 4 bases (represented by A, T, C and G) is condensed to a deoxyribose unit in the
sugar phosphate backbone. Each sugar/phosphate/base group is called nucleotide.
DNA consists of 2 strands twisted in a helical form with sugar-phosphate backbone around
the outside, held together by hydrogen bonding involving the internal base pairs.…read more

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Base pairing
Pairs of bases in DNA can form hydrogen bonds together-adenine and thymine, cytosine and
Chemists have found out that base pairing enables them to do 2 things
One strand with the aid of enzymes can synthesise and complementary copy of itself for
example TCGAT on the original strand will appear as AGCTA on the complementary
replicated strand.…read more

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The mRNA carries a code in the sequence of bases that corresponds to a particular amino
acids.-the code is a triplet code, with 3 bases coding for each amino acid .The group of three bases
is called a codon
Because there is 64 arrangements of 3 bases and 20 amino acids, the code is said to be degenerate
­there is more than one code for an amino acids.…read more


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