Chromosomes, Genes, DNA, Proteins Flashcards
What are chromosomes?
- thread like structures found in the nucleus
- made from DNA molecules
- can be grouped into pairs (humans have 23 pairs)
What does a DNA molecule contain?
- double helix: two strands facing each other
- four bases: A-T and C-G.
What does the order of the bases make up?
The genetic code: gives instructions for the assembly of a protein (amnio acids are in the protein and the order in which they’re arranged)
What is a nucleotide?
The basic unit of DNA
Phosphate: circle
Sugar: pentagon
Base: rectangle.
Where is the genetic code for protein synthesis found in plant and animal cells?
On the DNA in the nucleus.
Where does protein synthesis occur?
In the cytoplasm.
What is messenger RNA (mRNA)?
Produced in the nucleus, using DNA as the template (during which time the two strands of the DNA separate).
What does mRNA do?
It carries the instructions for the assembly of proteins (protein synthesis) into the cytoplasm.
What are ribosomes?
Proteins assembled on organelles in the cytoplasm.
What determines the type of protein and it’s properties?
The number and sequence of amino acids.
What determines the sequence of amino acids?
The genetic code.
What codes an amino acid?
When the bases work in threes (base triplets).
What is mRNA a copy of?
The base sequence of the DNA that makes up a gene.
Explain the journey of mRNA:
1) DNA unzips
2) mRNA copies DNA
3) mRNA moves to ribosome where proteins are made
4) protein chains leaves ribosome.
