bio.b.2. only one strand of dna is transcribed. complementary rna nucleotides are added to the dna...
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GENETICSBIO.B.2
PROTEIN SYNTHESIS(MAKING PROTEINS)
Only one strand of DNA is transcribed.
Complementary RNA nucleotides are added to the DNA strand.
DNA RNA A – U G – C T – A C – G
The Importance of Proteins
Each gene controls the making of a protein.
A gene is section of DNA that gives instructions for a specific protein to be made
20 amino acids make up all proteins
Proteins are required for almost every reaction that occurs in your body!
CODONS
Codon - three bases in a row that determine the amino acid that is used to make a protein.
mRNA Codon Chart
Some codons do not represent amino acids, but instead act as stop signals (the end of a protein).
Note, one amino acid may have more than one codon.
TRANSLATIONFROM mRNA TO PROTEIN
Begins when a ribosome attaches to a mRNA strand.
mRNA is used to make a specific protein (or polypeptide).
BIOTECHNOLOGYThe Golden Age of
Biology!
Gene Therapy
Bioinformatics
Stem Cell Research
Cloning
Bioremediation
Genetically Modified Organisms (GMOs)
Genetic Testing
Pharmacogenomics
Point Mutations
NormalAAT TAA TAG GAT TTT AAA
MutationAAT TAG TAG GAT TTT AAA
The G was used instead of an A.
Frame-Shift Mutations
Usually occurs as a result of an insertion or deletion
NormalTAC GCA TGG ATT
Insertion TAT CGC ATG GAT T
T was inserted after the A.
Example using words:
THE FAT CAT ATE THE RAT
THE FAT C AT A TE T HE R AT
TEF ATC ATA TET HER AT Just like this mutated sentence
does not make sense, frameshift mutations make nonsense proteins that cannot do their jobs correctly.
DELETION of H
Chromosomal Mutations Deletion – when part or all of a
chromosome is lost Duplication – when part of a chromosome
is mistakenly repeated Inversion – when part of a chromosome
becomes oriented in reverse of its normal direction
Translocation – when one part of a chromosome breaks off and attaches to another nonhomologous (not the partner) chromosome
Chromosomal Mutations
Deletion
Duplication
Inversion
Translocation
Cause of mutations
Mutagen – any agent that causes DNA to mutateUV lightRadiationSmokingMany different chemicals
Mutations gone wild Cats
Gene Regulation Only some of your genes are being
expressed (used to make protein) at any given time.
Your body needs mechanisms to “turn on” or “turn off” genes.
Chemicals can act as blocks or starters. Some cancers are caused by genes being
turned on that should not have been! For example, these genes can be turned on by smoking, which mutates DNA.
GENETICS
Genetics – the study of heredity or passing on of genes
Gene – a sections of DNA that codes for a protein to be made
Allele – the form that a gene takes (ex. dominant or recessive)
Homozygous – having the same alleles for a trait
Heterozygous – having different alleles for a trait
Dominant trait – an allele that is fully expressed in heterozygotes; represented by a capital letter
Recessive trait – an allele that is not observed in heterozygotes; represented by a lower case letter
Genotype – the combination of alleles (letters) that an organism has
Phenotype – the physical trait or visible characteristic determined by the genes
Link between meiosis and genetics:
SINGLE TRAIT CROSSES:
Incomplete Dominance Crosses:
Codominance Crosses:
Multiple alleles crosses:
Blood Types
BLOOD TYPES GENOTYPES ANTIGENS
(MARKERS)
ANTI-BODIES
(FIGHTERS)
RECEIVE FROM? DONATE TO?
TYPE A
TYPE B
TYPE AB
TYPE O
Blood Type Crosses:
Sex-linked Crosses: