National 5 Biology: KA3: DNA and the Production of Proteins Flashcards
Define:
Chromosomes
Thread-like structures found in the nucleus that contain genetic information.
Define:
Gene
Sections of DNA containing coded instructions for making a specific protein.
What shape is DNA?
Double helix structure
What are the rungs of the double helix?
DNA bases
What bonds DNA together?
Chemical units.
What do these chemical units do?
Bond as complementary base pairs to hold the double helix together.
Which bases pair with which?
A - T
C - G
Define:
Organism
Living being made of single or many cells
Define:
Cell
Basic unit of living things.
Define:
Nucleus
Organelle in cells which contains genetic information
Define:
Gene
Unit of inheritance which controls a characteristic.
Define:
DNA
Chemical which contains the genetic code.
Define:
Base pair
Small chemical units which make up DNA joined like rungs on a ladder.
Who was credited for the discovery of the structure of DNA? [3]
Francis Crick, James Watson and Maurice Wilkins
When was the discovery of the structure of DNA made?
In February 1953
Who else contributed to the discovery of the structure of DNA?
Rosalind Franklin.
What did Rosalind Franklin do?
Took an image of the structure (Photograph 51) - using x-ray crystallography.
Where was the discovery of the structure made?
Cambridge University
Who didn’t get a Nobel Prize for their work? Why?
Rosalind Franklin because she died of cancer in 1958 - four years before the prize was awarded.
What does DNA stand for?
Deoxyribonucleic acid
What do bases hold?
Genetic code.
What is the genetic code?
Instructions for how an organism will develop.
Specific patterns of bases give what?
Specific instructions
What does each chromosome contain?
Multiple genes.
What does each gene contain?
A specific sequence of DNA bases.
How many different DNA bases are there?
4
What are the 4 bases of DNA?
ATCG
adenine, thymine, guanine, cytosine
What did Chargaff discover?
Number of A’s = number of T’s
Number of C’s = number of G’s
What are proteins?
Long chains of amino acids folded into specific shapes.
Define:
Amino Acids
Building blocks of proteins
How many amino acids are there?
20
What is the order of amino acids determined by?
The DNA sequence
How does DNA become a protein?
DNA base sequence –> chain of amino acids –> protein
How many molecules of DNA are in a chromosome?
2
What are they held together by?
Hydrogen bonds
What does mRNA mean?
Messanger RNA
Why are the instructions for making proteins coped onto mRNA?
The instructions have to go through the cytoplasm to get to the ribosomes and during this journey, they could get lost / damaged.
What happens to the original / master copy?
Stays in the nucleus.
