DNA structure Flashcards
DNA and RNA similarities
both types of nucleic acid
both found in all living cells
both needed to build proteins - essential for proper functioning of cells.
both important information carrying molecules (although they have different functions.)
DNA function
store genetic information
contains the instructions for the growth and development of all organisms
RNA function
To transfer genetic code found in DNA out of the nucleus and carry it to the ribosomes in the cytoplasm.
Ribosomes are where proteins are produced - they read the RNA to make polypeptides (proteins) in a process called translation.
what are the monomers of DNA and RNA called
nucleotides
what is a nucleotide made of?
A pentose sugar
A nitrogen-containing organic base
A phosphate group
DNA nucleotides components
A deoxyribose sugar with hydrogen at the 2’ position
A phosphate group
One nitrogenous base
RNA components
A ribose sugar with a hydroxyl group at the 2’ position
A phosphate group
One nitrogenous base but thymine is replaced with uracil.
RNA and DNA differences
Pentose sugar (ribose and deoxyribose)
Bases (T for U)
Number of strands (double and single)
How do nucleotides join?
condensation reaction
what is the chain of alternating phosphate groups and pentose sugars called?
Sugar-phospate backbone.
Draw a DNA nucleotide
pentose sugar, labled as follows:
Oxygen at northen peak
1’ should be on right corner
The numbers should increase clockwise
attached to 1’ should be a nitrogenous base
a hydrogen should drop from 2’
phosphate group should comef rom 4’ and make a 5’ CH2 group.
Phosphate group is circle
nitrogenous base is rectangle
Pentose sugar is pentagon.
how do bases bond?
hydrogen bonds between complimentry base pairs.
complimentry base pairing.
how many hydrogen bonds between the bases?
T=A - 2
C≡G - 3
what is the double helix
the three dimentional shape that DNA molecules form.
Draw a RNA nucleotide
pentose sugar, labled as follows:
Oxygen at northen peak
1’ should be on right corner
The numbers should increase clockwise
attached to 1’ should be a nitrogenous base
a hydroxyl group should drop from 2’
phosphate group should comef rom 4’ and make a 5’ CH2 group.
Phosphate group is circle
nitrogenous base is rectangle
Pentose sugar is pentagon.
What are ribosomes made of? how does it help with making protiens.
RNA and protiens
(ribosomal RNA) - able to catalyse the formation of peptide bonds between amino acids.
what are 80S and 70S ribosomes made up of?
80S - 60S and 40S
70S - 50S and 30S
where are 70S ribosomes found?
Prokaryotic cells + mitocondria + chloroplasts.
what happens in the larger subunit of ribosomes?
translation
what happens in translation?
the rRNA hold tRNA in place
rRNA catalyses the condensation reactions between amino acids.
mRNA role in translation
sits between the two ribosome subunits and the ribosome moves along it as it translates it into a polypeptide.
ribosome membrane?
NO
Give me a rundown on why scientists didn’t believe in the model of DNA, remember to name the 3 people.
Doubted it could carry genetic code
too simple
only simple repeating nucleotides
20 different amino acids
4 different nucleotides
watson and crick confirmed double helix structure of DNA using Rosalind Franklin’s x-ray data.
