Protein Synthesis Flashcards
(15 cards)
How do cells make or synthesis proteins?
Cells make or synthesis protein by joining together amino acid units in the correct order.
How do you put together the bases A, T, G and C get together not in pairs but in triplets?
- Each protein is made up of large numbers of amino acid molecules.
- Each triplet of bases codes for one particular amino acid.
- Amino acids are made in the number and order dictated by the number and order of base triplets.
- Finally, the amino acid molecules join together in a long chain to make a protein molecule. The number and sequence of amino acids determines which protein results.
What do different shapes and sequences give proteins?
The different shapes and sequences give the proteins different functions.
Where is keratin found?
Keratin is a fibrous protein found in hair and nails.
What is transcription?
Transcription is the first part of the process of making a protein. It takes place inside the cell nucleus. Transcription involves copying the DNA.
What are the stages of transcription?
- The strands of DNA separate.
- Stands of mRNA form as the bases of RNA nucleotides combine with their complementary bases of the single-stranded DNA.
- The strands of mRNA separate from their respective complementary strands of DNA. They pass from the nucleus through gaps.
What is translation?
Translation takes place in the ribosomes that are found in the cytoplasm. This is where the messenger RNA is ‘interpreted’ and the new protein formed.
What are the stages of translation?
- Each strand of mRNA binds to a ribosome forming an mRNA-ribosome complex.
- Each type of tRNA molecule binds to its particular type of amino acid dissolved in the cytoplasm, depending on the triplet of bases (codon) it carries.
- tRNA/amino acid combinations pass to the mRNA-ribosome complex. The exposed bases of each rRNA bind to their complementary bases on the mRNA. Chemical bonds form between the amino acids next to each other.
- Once the bonds form, each rRNA separates from its amino acid and the mRNA strand.
- The linked amino acids form a polypeptide.
How is a mutation inherited by offspring?
A mutation is inherited by offspring if a sperm or an egg that carry a mutated gene fertilise with one and other.
What are some of the effects of mutations?
Sometimes these changes can be so severe that the cell dies, sometimes the cell can divide uncontrollably and become cancerous, and sometimes the changes are small and the cell survives. Very rarely, the changes may even be beneficial to us and produce new and useful characteristics.
How can a new species be made as a result to mutations?
The combined effect of these mutations, environmental changes, and natural selection, can sometimes produce changes in the organism that are so great that a new species is produced.
What is a silent mutation?
If a mutation changes a codon to an alternative (substitution) that still specifies the same amino acid, and the sequence of codons (including the mutated codon) is unchanged, the the amino acid sequence and the structure of the protein remains unchanged.
Where is messenger RNA made?
Messenger RNA is made in the nucleus.
Where does the messenger RNA move to in order to be “read”?
Messenger RNA moves to the ribosomes in order to be read.
What is the name of the long chain of amino acids that is formed?
A polypeptide chain is formed from the amino acids.
