220 likes | 330 Views
Tuesday January 29 th 2013. QU: What holds all of your genetic information? Where is it located? OBJ: New Seats, Introduction to DNA. Intro to DNA. DNA Structure. DNA is located in the nucleus DNA stands for DEOXYRIBOSE NUCLEIC ACID DNA is a type of nucleic acid
E N D
Tuesday January 29th 2013 • QU: What holds all of your genetic information? Where is it located? • OBJ: New Seats, Introduction to DNA
DNA Structure • DNA is located in the nucleus • DNA stands for DEOXYRIBOSE NUCLEIC ACID • DNA is a type of nucleic acid • Like starch is a type of carbohydrate • DNA is made of repeating subunits called NUCLEOTIDES
Chromatin • In the nucleus, DNA is found on long, thin fibers called Chromatin • Chromatin consists of DNA wound around proteins called histones • Next the DNA is wrapped into a tight helical formation
Chromosomes • When a cell is preparing to divide, chromatin condense into chromosomes • The human somatic cell (body cell) has 46 chromosomes = diploid • 23 from mom + 23 from dad = 46 total • An egg and sperm cell only has 23 = haploid
Chromosomes • Before a cell divides, it replicates all of its chromosomes • Each chromosome now consists of 2 identical joined copies called sister chromatids • Each sister chromatid is joined by a centromere
Chromosome Sister Chromatids
Genes • A section of DNA that codes for a specific trait • You have thousands and thousands of genes
WedNesday January 30th 2013 • QU: When DNA is coiled up what is it called? OBJ: Discovering DNA Structure
DNA • There are 4 different types of nucleotides that can be used to build DNA • This is because there are 4 different nitrogen bases that can be used • Adenine (abbreviated A) • Guanine (G) • Thymine (T) • Cytosine (C)
DNA: Purine versus Pyrimidine • PURINE: Have two rings • To be PURE is Always Good. • Adenine and Guanine • PYRIMIDINE: Have only one ring • The other two • Cytosine and Thymine
DNA • *Strands are connected by hydrogen bonds* (between bases) • DNA overall structure is called a DOUBLE HELIX
Thursday January 31st 2013 • QU: Write the complement to the following strand. A T G C C G T A • OBJ: DNA Replication “The most poisonous snake in the world is Belcher's Sea Snake or the Faint-banded Sea Snake (Hydrophisbelcheri).”
DNA Replication • If I said a painting was a replica (or replicated) what does that mean? • Why do you think it is important that we can replicate DNA?
DNA Replication… New nucleotides come in and base pair with the “open” original strand. Results in two strands of DNA The DNA has been copied Each DNA molecule has one original strand and one new strand • Process of copying the DNA molecule DNA Polymerase separates the bases by breaking the hydrogen bonds holding them together Original DNA strand Nitrogen bases paired up according to base pairing rules
Replication • This type of replication is known as semi-conservative replication • Start with one helix split into two separate strands but never “throw away any strands”
Friday FebRuary 1st 2013 • QU: Replication is __________ because the strands are split and each strand is used in a new DNA molecule. • OBJ: Quiz, Replication, Replication Review