Chapter 12

-Human-Genome-Project-Video--3D- Animation-Introductionwww.dnatube.com/video/2933/The -Human-Genome-Project-Video-

DNA is shaped like a double helix (a twisted ladder) This shape was discovered by two scientists: James Watson & Francis Crick

A T T A C G G C DNA – Deoxyribose Nucleic Acid DNA is made up of 4 parts: 1. Hydrogen bonds – they connect everything together 2. Sugars – Deoxyribose 3. Phosphate Groups 4. Nitrogen Bases – the part that carries the code Thymine always goes across from Adenine Guanine always goes across from Cytosine Nucleotide - is made up of a sugar, phosphate, and a nitrogen base.

DNA Replication – when the DNA makes a copy of itself DNA replication is important during mitosis because it makes sure the new cells have the same number of chromosomes as the parent cells If the original strand of DNA is AATTGGCC The complementary strand of DNA is TTAACCGG

Nitrogen Bases Only 4, broken into two groups. Purines Adenine – A Guanine - G Pyrimidines Thymine – T Cytosine – C

DNA functions: 1.holds the directions for protein synthesis 2. A blueprint for an individual Protein synthesis is the process of making proteins A gene carries the code for making one prot ein

Use pg 329 and 331

Everything in you is made of or by proteins! Protein Examples Hemoglobin is a protein in your blood that transports oxygen Collagen is a protein that makes your cartilage and tendons Keratin is a protein that makes up your hair & fingernails Enzymes are proteins

RNA – Ribose Nucleic Acid RNA is like DNA except… - it is single stranded - it has uracil instead of thymine - it has ribose instead of deoxyribose Nitrogen Bases Sugars & Phosphates RNA DNA

3 Forms of RNA 1. mRNA  messenger 2. tRNA  transfer 3. rRNA  ribosomal

Transcription (the first part of Protein Synthesis) A type of RNA, called mRNA (messenger) goes into the nucleus and copies the DNA The next step is that mRNA moves from the nucleus to the cytoplasm. DNA – ATCG mRNA - UAGC Animation Link

Translation (the second part of Protein Synthesis) mRNA then attaches to ribosomes. Another form of RNA called tRNA (transfer) carries amino acids tRNA only has 3 Nitrogen bases (anticodon) The tRNA lines up with 3 bases in mRNA (codon) tRNA anticodon AUG mRNA codon UAC The tRNA drops off the amino acid in the correct spot Amino acids lined up make a protein Different orders of amino acids make different proteins Amino acids are the building blocks of proteins Animation Link

Translation

UCAG U Phenylaline Leucine Serine Tyrosine Stop Cysteine Stop Tryptophan UCAGUCAG C Leucine Proline Histidine Glutamine Arginine UCAGUCAG A Isoleucine Methionine Threonine Asparagine Lysine Serine Arginine UCAGUCAG G Valine Alanine Aspartic acid Glutamic acid Glycine UCAGUCAG

Assignment Book pg 353 –6,7, Translate the following to RNA, then find the corresponding Amino Acids –TACTTGATGCCGGATATC

Any change in the DNA structure (specifically the order of nitrogen bases) is a mutation. Mutations can be helpful, harmful, or neutral. Helpful – can create diversity in a population Harmful – can cause things like cancer Neutral – has no effect A mutagen is something that causes mutations in the DNA (for example: smoking, radiation from the sun etc)

An insertion mutation is when a nitrogen base is added to the existing DNA A deletion mutation is when a nitrogen base is subtracted from the DNA A substitution mutation is when one nitrogen base is put in place of another. If our DNA was AATTGGCC An insertion would be AATTAGGCC A deletion would be AATGGCC A substitution would be AAATGGCC

DNA Fingerprinting – technique used in criminal investigations. DNA Fingerprinting takes the DNA out of a cell and separates it. This will allow investigators to distinguish body cells of different individuals (since they are unlikely to have the same DNA) Cloning – take the DNA out of one of your cells then take the DNA out of a zygote (fertilized egg). Put the DNA from your cell into the zygote.

Donor Nucleus An egg cell is taken from an adult female cow. The embryo develops normally into a calf. The embryo is placed in t he uterus of a foster mother. The nucleus of the egg cell is removed The two cells are fused using an electric shock The fused cell begins dividing normally Cow B Cow C Calf Embryo Egg Cell Donor cell taken from the cow. Fused Cell Cow A

Recombinant DNA is formed by joining DNA molecules.from two different organisms