DNA & Proteins Flashcards
(19 cards)
Name the shape of DNA and its contents.
DNA is a double standard helix held by complimentary base pairs
What does DNA carry?
Do you know, carries genetic information for making proteins
Name the four DNA bases
Adenine, cytosine, guanine and thynine.
Describe the DNA base pairing rule
A is always pair with T and C always pair with G
What does the base sequence determine?
The base sequence determines amino acid sequence in proteins
Define the term gene
A gene is a section of DNA, which codes for a protein
Describe the role of a messenger mRNA
mRNA is a molecule, which carries a complimentary copy of the genetic code from the DNA, in the nucleus, to a ribosome , where the protein is assembled from amino acids
State that the variety of protein shapes and functions arises from the sequence of amino acids
Give the functions of the following protein types; structural, enzymes, hormones, antibodies and receptors
Structural proteins offer help to the cells.
Enzymes proteins speed up chemical reactions for remain unchanged from the reaction.
Antibodies attack and destroy bacteria.
Hormones are chemical messengers
Receptors respond to signals and transmit messages to the interior of the cell.
State that enzymes function as biological catalysts and are made by all living cells
Describe the role of enzymes
Enzymes speed up cellular reactions and are unchanged in the process.
What does enzyme substrate complex form?
facilitating reactions
Describe the role of the active site of an enzyme
The shape of the active site of the enzyme molecule is complimentary to It’s specific substrate(s)
Give an example of an enzyme which carries out degradation reaction, including its substrate and product
Degradation reactions break molecules down, for example amylase breaks down
starch into maltose.
What do synthesis reactions do?
Build up molecules
Give an example of an enzyme which carries out a synthesis reaction, including its substrate and product
Synthesis reactions build molecules up for example phosphorylase builds up glucose-
1-phosphate into starch.
Explain the term optimum conditions
Each enzyme is most active in its optimum conditions.
Name two factors which can affect enzyme activity
Temperature and pH
Explain what happens to an enzyme when it is heated far beyond its optimum temperature
Enzymes can be denatured, resulting in a change in their shape which will affect the
rate of reaction.
