Genes And Enzymes

Question 1

What makes bacteria different from most forms of life

Answer 1

They do not have a nucleus but inst ad have chromosomal DNA and plasmid

Question 2

Who discovered DNA and what did they do to discover it?

Answer 2

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

Question 3

What is protein Synthesis

Answer 3

The process of making proteins in the ribosome

Question 4

How does protein synthesis works?

Answer 4

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.

Question 5

What can mutations be

Answer 5

They can be harmful, such as cystic fibrosis , beneficial it could provide new characteristics I.e resistance to antibiotics
Neutral

Question 6

What are enzymes

Answer 6

Enzymes are biological catalyst s

Question 7

What must be controlled to get the maximum efficacy from enzymes

Answer 7

Temperature, pH and substrate

Question 8

Describe genetic engineering

Answer 8

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.

Question 9

What benefits of genetic engineering

Answer 9

Reducing vitamin A deficiency by making golden rice
Producing human insulin in bacteria
Increasing the crop yield by making the plants resistant to herbicides.

Question 10

Why do mitosis

Answer 10

To make new diploid body cells for growth and repair

Question 11

What does diploid mean

Answer 11

There are two versions of each chromosomes

Question 12

What does mitosis create

Answer 12

Two identical cells to the original each has chromosomes in a nucleus they are diploid

Question 13

Explain the process of mitosis

Answer 13

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.

Question 14

How does A sexual reproduction happen.

Answer 14

They use mitosis

Question 15

What does a plant cell have which is absent from an animal cell

Answer 15

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,

Question 16

What does bacteria have that is unique

Answer 16

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

Question 17

What is the structure of DNA

Answer 17

It is a Double Helix

Question 18

Who discovered DNA

Answer 18

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

Question 19

How can you extract DNA

Answer 19

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

Question 20

What are the base pairs joined together with

Answer 20

Weak hydrogen bonds

Question 21

What does mRNA and tRNA stand for

Answer 21

Messenger RiboNibonuclicacid and TransferRnA

Question 22

Describe the parts of enzymes

Answer 22

The active site is where the substrate binds with the enzyme to catalyse the reaction

Question 23

Describe enzyme catalysing reactions in relation to a lock and key method

Answer 23

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

Question 24

Which variables effect enzymes

Answer 24

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

Question 25

What does meiosis create

Answer 25

Meiosis creates 4 haploid cells or gametes

Question 26

Describe the process of meiosis

Answer 26

First the chromosomes create an exact replica of themselves to form “x shaped chromosomes”. Similar chromosomes pairs come together and sections of the DNA are swapped. The pairs of chromosomes then divide by mitosis. This creates 2 diploid genetically varied cells. The cells then divide again creating haploid cells they have half the number of chromosomes and they are mixed.

Question 27

Describe the process in which cloning happens

Answer 27

First remove the nucleus from an egg cell to create an enucleated cell. Remove the nucleus from an adult body cell from the organism you wish to clone. Insert the diploid nucleus into the empty egg cell. Start the division of mitosis by stimulating the cell with electric signal or hormones. Insert the embryo into a surrogate mother.

Question 28

What are uses of cloning

Answer 28

To create organs for transplants
Studying animal clones can lead to a greater understanding of embryo and ageing
To help save endangered species.

Question 29

What are the disadvantages of cloning

Answer 29

It creates a reduced gene pool which leads to less resistance to infections meaning they are more dangerous.
Cloned mammals don’t live as long, dolly the sheep lived 6 years half the life of a normal sheep.
Cloning often fails meaning embryo’s are wasted, clones are born with genetic defects

Question 30

What is the process of cells becoming adapted for certain tasks called

Answer 30

Specialisation or differentiation

Question 31

What are extremely useful types of cells for healing

Answer 31

Embryonic Stem cells. They can differentiate into many different types of cells so a versatile. Adults only have stem cells in bone marrow but these aren’t. Versatile as embryonic stem cells.

Question 32

Why are stem cells useful

Answer 32

Stem cells can replace damage cells or tissues I.e new cardiac muscle for those with heart disease. This has potentially new cures

Question 33

What are concerns with stem cells

Answer 33

They come from embryos some say these are human life’s and therefore there creation and destruction for research is murder.