Protein Synthesis. Identify the structure and function of DNA, RNA, and proteins. Recognize...

Protein Synthesis

Identify the structure and function of DNA, RNA, and proteins.

Recognize diagrams of DNA and RNA, sugars, phosphate groups, nitrogenous bases.

Understand Complimentary base pairing.

How DNA is replicated

Stands for Deoxyribonucleic Acid Type of Nucleic Acid What chromosomes and genes are

made of. Made of repeating nucleotide sub-

units.

2 types of Nitrogen Bases Purines Double ring G & A Pyrimidines Single ring C & U & T

Erwin Chargaff discovered the base pairing rules and ratios for different species.

Adenine pairs with Thymine Cytosine pairs with Guanine

Complementary: bases on one strand match up with the bases on the other strand (A-T and G-C)

Example: Strand 1- ATG GGC Strand 2- Codon: Group of 3 bases

History Rosalind Franklin took first picture

of DNA using a X-ray machine.

The Nobel Prize in Medicine 1962 James Watson & Francis Crick

interpreted the photo and discovered the double helix structure.

Genes: Stretch of DNA that codes for a trait.

The code is the order of the bases (letters).

Genes are hundreds or thousands of bases long.

  The genetic code is a sequence of

DNA nucleotides in the nucleus of cells.

During S stage in interphase, DNA replicates itself.

DNA replication is a semi-conservative process.

Semi-conservative means each new piece of DNA is made up of 1 old strand and 1 new strand.

  You end up with 2 identical strands

of DNA.

A copy of DNA that goes out into the cytoplasm to tell the cell what to do in order to stay alive

RNA= Ribonucleic Acid You can always make more RNA,

but no more DNA.

Single strand instead of double strand

  Ribose instead of deoxyribose   Uracil instead of thymine

Definition: RNA is made from 1 gene in DNA

The type of RNA made is called mRNA (messenger RNA) because it sends a message from DNA to the cytoplasm

Transcription Unzip one gene in DNA Match up bases to one side of gene in

DNA mRNA detaches from the DNA mRNA moves out of the nucleus and into

the cytoplasm         DNA: GAG AAC TAG TAC ACC TAT CGG

GGG CAT RNA:

mRNA is a message that codes for a protein

Proteins are made in the cytoplasm and then work to keep the cell alive

Proteins are made up of amino acids (small building blocks)

There are 20 different types of amino acids

What causes mutations? A change in the DNA sequence A mistake that’s made during replication

or transcription Can be harmful: diseases or deformities Helpful: organism is better able to

survive Neutral: organism is unaffected If a mutation occurs in a sperm or egg

cell, that mutation is passed on to offspring

If a mutation occurs in a body cell, that mutation affects on the organism and is not passed onto offspring.

Point Mutations or Substitutions: bases are mismatched

Harmful when: a mistake in DNA is carried into mRNA and results in the wrong amino acid.

Not harmful when: a mistake in DNA is carried out into mRNA but still results in the correct amino acid.

Example: Sickle Cell Anemia Types of mutations Frame Shift Mutations: bases are

inserted or deleted. Are usually harmful because a

mistake in DNA is carried into mRNA and results in many wrong amino acids.

Ex.: Crohn’s disease

Chromosomal mutations: Chromosomes break or are lost

during mitosis or meiosis. Broken chromosomes may rejoin

incorrectly Almost always lethal when it occurs

in a zygote. Ex.: hemophilia,a bleeding disorder

Mutagens: anything that causes a change in DNA

Examples: x-rays, UV light, nuclear radiation, asbestos, cigarette smoke

A complex system of enzymes, active in the G2 stage of interphase, serves as a back up to repair damaged DNA before it is dispersed into new cells during mitosis.

The Human Genome Project is a collaborative effort of scientists around the world to map the entire gene sequence of organisms.

  This information will be useful in

detection, prevention, and treatment of many genetic diseases.

DNA technologies allow scientists to identify, study, and modify genes.

  Forensic identification is an

example of the application of DNA technology.

Gene therapy is a technique for correcting defective genes responsible for disease development.

Possible cures for: diabetes cardiovascular disease cystic fibrosis Alzheimer's Parkinson’s and many other diseases is possible.

The human manipulation of the genetic material of a cell.

Recombinant DNA- Genetically engineered DNA prepared by splicing genes from one species into the cells of a different species. Such DNA becomes part of the host's genetic makeup and is replicated.

Genetic engineering techniques are used in a variety of industries, in agriculture, in basic research, and in medicine.

There is great potential for the development of useful products through genetic engineering

EX., human growth hormone, insulin, and pest- and disease-resistant fruits and vegetables

We can now grow new body parts and soon donating blood will be a thing of the past, but will we go too far?