Chapter 8.2 The Genetic Code New Material Flashcards
What are proteins?
Long-chain molecules made of individual amino acids
What determines what type of protein will be produced?
The order of the nitrogen bases along a gene forms a genetic code that specifies what type of protein will be produced
What is a codon?
A group of 3 bases in the genetic code that codes for one specific amino acid
Ex. CGT = amino acid Alanine
The first 3 codon determine the specific amino acid that will be produced. What do the other codon determine?
The order in which the amino acids are put together to form a protein
How many different amino acids are in the human body?
20
What does your body use amino acids for?
To make different types of proteins needed to carry out cell processes.
What is protein synthesis?
When the amino acids link to form proteins
Where does the process of protein synthesis begin?
INSIDE the nucleus where DNA contains the code for the protein
Where does the assembly of the protein occur?
OUTSIDE the nucleus on a ribosome
How does the blueprint for making a protein get from the nucleus to the ribosome?
By a nucleic acid called RNA (ribonucleic acid)
How is RNA different from DNA?
RNA contains the sugar ribose instead of deoxyribose
What nitrogen base is different berween RNA and DNA?
RNA had uracil (U) instead of thymine (T)
Uracil (U) is the complement to adenine (A) in RNA
What are the two types of RNA?
mRNA - messenger RNA
tRNA - transfer RNA
What is mRNA
Messenger RNA carries copies of instructions for the assembly of amino acids into proteins from DNA to ribosomes in the cytoplasm
What is tRNA?
Transfer RNA carries amino acids to the ribosome during protein synthesis.
What is an mRNA codon table?
It is a table used by scientists to determine which codons will code for each amino acid.
What is a mutation?
Any change in a gene or chromosome.
How do mutations occur?
They can be inherited from a parent or acquired during an organism’s life.
What are inherited mutations?
- Occur when the parent passes on the mutation during reproduction.
- Present through the life of the organism
- Present in every cell of the body
What are acquired mutations?
- Occur at some point during an organism’s lifetime
- Can only be passed on from parent to offspring if the mutations occur in sex cells
- Are not present in every cell of the body
NOTE: number 2 does not make sense to Mom
Acquired mutations can be caused by environmental factors such as ultrviolet radiation from the sun or if an error is made when DNA copies itself during cell division
What causes mutations?
Many mutations are the result of a small change in the organism’s DNA sequence.
Mutations include deletion, addition or substitution.
What may happen if there is a small change to a base pair in DNA?
An incorrect protein may be made during protein synthesis
What are sex-linked mutations?
They occur on sex-linked genes which are on the sex chromosome
Which chromosome do most sex-linked mutations occur?
The x chromosome because it has more genes than the y chromosome.
Are sex-linked mutations dominant or recessive?
Recessive
What are some examples of sex-linked mutations?
Hemophilia - ability of blood to clot is reduced
Color-blindness
