Biology - DNA, PROTEINS, ENZYMES Flashcards
Describe dna
Double stranded helix held together by complementary base pairs
Name the complementary base pairs
Adenine+thymine
Guanine+cytosine
What is the function of DNA
sequence of bases determines the sequence of amino acids in proteins
What is mRNA
A molecule which carries a complementary copy of the genetic code
Where does mRNA go ?
From dna
In the nucleus
A
To a ribosome
What happens in the ribosomes
Proteins are assembled from amino acids
How are amino acids coded
Sequence of three bases
What is a gene
Section of dna codes for proteins
Where is dna found
Nucleus of chromosomes
DNA CANNOT LEAVE NUCLEUS
What does DNA carry
Genetic information for making proteins
What are chromosomes and their genes made up of
DNA
List 3 types of proteins
Structural
Enzymes
Hormones
What does the sequence of amino acids determine
The shape and function of the protein
What are enzymes are where are they found
Proteins found in all living cells
What are enzymes functions
A biological catalyst
What is a biological catalyst
Speeds up the rate of chemical reactions and remains unchanged in the process
What is the shape of the active site of an enzyme complementary too
It’s specific substrate (s)
What is the enzyme formula
Substrate —— enzyme ——product
What are substrates
Chemicals enzymes act upon
What are products
Chemicals produced by action of an enzyme
What is hydrogen peroxide
A substrate
What is catalase
An enzyme
What is water and oxygen
Products
What is a degradation reaction
A large molecule is broken down into smaller products
What is a synthesis reaction
Build up of smaller substrates into larger products
What is the part of an enzyme that substrate molecules can attach to
The active site
What is the active site of an enzyme molecule complementary too
A specific substrate - an enzyme can work on one substrate
Where is an enzyme most active
It’s optimum condition
What is the optimum condition
Where an enzyme is most active / highest rate of reaction
What can enzymes and other proteins be affected by - give examples
Temperature and ph
What does denatured mean
Enzymes can become denatured resulting in a change in shape which will affect the rate of reaction
When will an enzyme denature
At a high temperature
What happens when a denatured enzyme changes shape
Substrates can no longer bind
What happens to enzymes at an optimum pH
They are most active
What happens if the pH value increases above or decreases below the optimum pH
The enzyme activity decreases
What happens if temperature increases beyond a proteins working range
The shape of proteins irreversibly changes
What is a control used for
To prove that it is the independent variable that is changing the dependent variable and no other factors
What does a control allow
A comparison
Give 4 examples of controls
Time durations
Mass/volumes
Temperature
Concentration of substances
