Genes And Enzymes Flashcards
(33 cards)
What makes bacteria different from most forms of life
They do not have a nucleus but inst ad have chromosomal DNA and plasmid
Who discovered DNA and what did they do to discover it?
Waston, Crick, Franklin and Wilkins
Rosalind Franklin and Maurice Wilkins worked out that DNA had a helix structure by directing beams of x-Ray’s onto DNA
James Watson and Francis Crick they modelled the DNA
What is protein Synthesis
The process of making proteins in the ribosome
How does protein synthesis works?
The two DNA strands unzip and the DNA is a template to make mRNA, this is called transcription . Thymine is replaced with uracil.
mRNA moves out and joins with the ribosome , tRNA here brings amino acids that match mRNA code. Or codon
The ribosome stick amino acids together to made a chain or polypeptide. This is called translation
This folds to create a protein.
What can mutations be
They can be harmful, such as cystic fibrosis , beneficial it could provide new characteristics I.e resistance to antibiotics
Neutral
What are enzymes
Enzymes are biological catalyst s
What must be controlled to get the maximum efficacy from enzymes
Temperature, pH and substrate
Describe genetic engineering
Cut a the gene you want from the DNA using restriction enzymes cut the hole in the human DNA also using restriction enzymes. This creates sticky ends which means the base pairs will join up.
What benefits of genetic engineering
Reducing vitamin A deficiency by making golden rice
Producing human insulin in bacteria
Increasing the crop yield by making the plants resistant to herbicides.
Why do mitosis
To make new diploid body cells for growth and repair
What does diploid mean
There are two versions of each chromosomes
What does mitosis create
Two identical cells to the original each has chromosomes in a nucleus they are diploid
Explain the process of mitosis
The chromosomes line up at the centre of the cell and the DNA is duplicated. Spindle fibres pull them apart to opposite sides of the cell. Membranes form around each set of the chromosomes, they become the nuclei of the new cells. Lastly the cytoplasm divides creates two new diploid cells which are genetically identical.
How does A sexual reproduction happen.
They use mitosis
What does a plant cell have which is absent from an animal cell
It has chloroplasts which are used for photosynthesis it has a vacuole which stores the cells sap and gives it structure. It has a cell wall made of cellulose,
What does bacteria have that is unique
It has plasmid DNA which is mutable meaning it can change I.e genes such as drug resistance which can be passed between bacteria . Chromosomal DNA which is one long strand of DNA it floats free in the cytoplasm
What is the structure of DNA
It is a Double Helix
Who discovered DNA
Two teams
Franklin and Wilkins fired x-Ray beams at DNA and studies the patterns X-rays formed a they bounced off. They discovered the helical structure
Watson and Crick used the ideas as well as knowledge that admins and thymine matched the amount of guanine and cytosine to model it
How can you extract DNA
First place the DNA in detergent and salt to breaks down the membrane and stick the DNA together.
Place the solution in a water bath so enzymes denature and cannot decay DNA. Put in ice to stop breaking down. Place in blender to break open the cell wall and release the DNA. Cool it again and add alcohol the DNA will come out as it is insoluble
What are the base pairs joined together with
Weak hydrogen bonds
What does mRNA and tRNA stand for
Messenger RiboNibonuclicacid and TransferRnA
Describe the parts of enzymes
The active site is where the substrate binds with the enzyme to catalyse the reaction
Describe enzyme catalysing reactions in relation to a lock and key method
The lock and key hypothesis states that a specific enzyme can only fit a specific substrate. Therefore if the enzyme changes its shape it will no longer be able to catalyse reactions. Enzymes have a high specificity for their substrate
Which variables effect enzymes
pH certain enzymes only work in certain conditions for instance pepsin a protease only works in pH 3 in the stomach. To much change either side will result in denaturing
Temperature, above 37 degrees enzymes begin to denature however below they just slow down (collision theory)
Substrate concentration, the higher the concentration the faster the reaction up to a point where all active sites are being used all times
