What is a Nucleus?
Gel-like substance where most of the cell's chemical reactions happen.
The part of the cell which contains DNA in the form of chromosomes
Where proteins are synthesised
A cell membrane is...
where most of the reactions involved in respiration take place.
what holds the cell together and controls what goes in and out.
a gel-like substance where most of the cell's chemical reactions happen.
What is a ribosome?
Where proteins are synthesised.
The part that holds the cell together and controls what goes in and out.
Where most of the reactions involved in respiration take place.
Cytoplasm is...
the part of the cell which contains DNA in the form of chromosomes.
a relatively large structure that contains cell sap, a weak solution of sugar and salts.
What is Mitochondria?
Where most of the reactions involved in respiration occur.
Where photosynthesis happens.
Another name for a bacterial cell.
Cells that need lots of energy contain many mitochondria. Which cells need lots if mitochondria?
Liver and Muscle cells.
Plant cells.
Every cell.
Instead of a nucleus, what do bacterial cells have?
Chloroplasts.
A single-circular strand of DNA.
Mitochondria.
What are Chromosomes?
Cell malfunctions.
Long molecules of coiled up DNA.
Enzymes.
DNA is a double helix (a double stranded spiral). Each of the two DNA strands are made up of what?
Proteins.
Cricks.
Nucleotides.
Nucleotides contain a small molecule called a "base". How many bases are there and what are they called?
3-BOE
5-TRLE
4-ACGT
Each base forms cross links to a base on the other strand. This keeps the two DNA strands tightly wound together. But which base pairs, pair with each other?
A pairs with G, and T pairs with C.
A pairs with T and C pairs with G.
T pairs with G and A pairs with C.
Who were the first scientists ever to build a model of DNA?
Catson and Wrick.
Darwin and Lamarck.
Watson and Crick.
What data did Watson and Crick use from other scientists to form the model of DNA?
X-Rays showing double helix and data showing that bases occurred in pairs.
An X-ray of a skeleton.
Graphs showing DNA shrinking.
What does DNA do every time a cell divides?
Adds another strand.
Adds another "base" called O.
Copies itself so that each new cells still has the full amount of DNA.
What do new nucleotides do during this process?
Break up.
Join on using complementary base-pairing (ATCG). Making an exact copy.
Lose base pairs.
Which is correct?
|-TA-| |-AC-| |-GT-| |-GA-| |-AT-|
|-TA-| |-AT-| |-GC-| |-GC-| |-AT-|
What does DNA control the production of?
Oxygen.
Blood.
A section of DNA that codes for a particular proteins is called a...
Enzyme.
Nucleus.
Gene.
Proteins are made up of chains of molecules called what?
Cells.
Amino Acids.
Each different protein has its own particular number and order of amino acids.
If each protein has its own particular number and order of amino acids, does this give the proteins a different shape or a different function?
Yes
No
How many bases is an amino acid coded by?
4. (Quad)
2. (Pair)
3. (Triple)
The amino acids are joined together to make proteins, following how many bases there are in a gene.
So, why does each gene contain a different sequence of bases?
So it can produce more cells.
So it can code for a unique protein.
What carries the code to the Ribosomes?
DNA.
mRNA.
Where are the ribosomes?
The Nucleus.
The Cytoplasm.
The Mitochondria.
To make proteins, ribosomes use the code in the DNA. DNA is found in the cell nucleus an can't move out of it because...
DNA is really big.
The DNA will get lost.
DNA is really small.
If the DNA can't leave the cell then another molecule is needed to get the code from the DNA to the Ribosome. This is called mRNA. How is it used?
It takes the code from the DNA.
It produces more DNA.
It copies the code from the DNA.
DNA controls a cell by...
turning the cell on and off.
controlling protein production.
making more DNA.
Different types of cell have different functions because they make different proteins.
Why do some genes switched off?
So certain proteins are not produced.
So more proteins can be produced in different places.
In a muscle cell, which genes are switched on and which are switched off?
Bone, nerve and skin cells are switched on and muscle cells are off, to conserve energy.
Or are muscle cells switched on and bone, nerve and skin cells are switched off.
What is the function of a carrier molecule?
To carry messages around the body.
Strengthen connective tissues.
To transport smaller molecules.
What is the function of a hormone?
To produce proteins. e.g. muscle proteins.
To carry messages around the body. e.g. insulin.
To strengthen connective tissues.