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: 

Pedigree: 

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: