Sunday, November 7, 2010

Enzyme Lab

Temperature
5 pieces of enzyme discs used per experiment
5 ml of peroxide used per experiment
each experiment was shook throughout the whole duration

room temperature:
peroxide temperature : 22 degrees Celcius
 570 ml of O2 gas produced in 30 seconds

hot :
peroxide temperature:  60 degrees Celcius
200 mL of O2 gas produced in 30 seconds

Cold:
peroxide temperature :  6 degrees Celcius
100 mL of O2 gas produced in 30 seconds

Saturday, October 23, 2010

4 macromolecules

Lipid :
types of lipids:
-triglycerides
-fatty acids
-steroids
-phospholipids
roles:
-insulation,f ood, digestion, vitamin, hormone
Triglycerides: 3 fatty acids + glycerol
saturated fat:   packed, no space for reaction in fat fat cell
unsatured fat: room for reaction due to double bonds, less stable
steroids: 4 carbon rings
protein:
roles:
-bluk composition of body
-oxidative metabolism
-enzymes
-plasma proteins
-hormones
Structure of protein:
-sequences of amino acids hooked together by amino group of one to carboxyl group of another
-peptide linkage
-amino acid found in protein are known as residues
4 types of protein structures:
Primary : sequence of AA's forming protein ( one strand)
Secondary : alpha helix design or beta pleated sheet
Tertiary :  bending of one amino acid chain due to attraction of individual amino acid's distant from each other ( possible linkage such as : hydrogen bond, disulfide bridge, ionic bond)
Quaternary: packing of chains together
Amino acids:
-number and proportion of amino acids vary from protein to protein
-amino acids would remain in denatured proteins
  Essential AA:  those animals  cannot   synthesize ( one that animal  receive from diet)
Nonessential: synthesize by animal
DNA :
monomers:   nucleotides ( phosphate , sugar , nitrogenous base
Deoxyribose: main sugars in genetics
phosphate form bonds with group 3 of 2-deoxyribose
4 nitrogenous base :
adenine
cytosine
genine
thymine 
purines(A ,G)
pyrimidine (CT)
3 bonds:
glycosyl
phosphodiester
hydrogen bond

phosphodiester bond between O from phosphate group with carbon 5 of deoxyribose
glycosyl bond between nitrogenous base with OH on carbon 1
 hydrogen bond between nitrogenous bases

Carbohydrates:
basic composition: CH2O
Monosaccharides:
-simple sugars with OH groups
-triose, tetrose, pentose or hexose
 aldoses:
-aldehyde group at one end
 ketose:
- keto group usually at C2

Pentoses and hexoses can cyclize as ketone or aldehyde reacts with a distal OH.
D-glucose (linear) ---> Alpha-D glucose or Beta- D Glucose ( differ by the position of OH on C1 above or below ring)
-the 2 stereoisomers are anomers (alpha and beta)
-OH at the anomeric C1
- alpha :  OH below ring
-beta:  OH above ring
D-fructose( linear) ---> Alpha- D- fructose 
-by reaction of C2 keto group with OH on C5

Glycosidic bonds: R- OH    + HO- R prime  ---> R-O-R prime +H2O
anomeric hydroxyl and hydroxyl of another sugar or other compound --> splitting out water to form glycosidic bond (result of condensation)
ex: glucose +glucose--> maltose +water
hydrolysis:
ex: sucrose +water --> glucose+fructose

Disaccharides: 2 monosaccharides covalently linked
Polysaccharides: polymers consisting chains of monosaccharide or disaccharide
Amylose: glucose polymer with alpha(1->4) linkages
amylopectin: glucose polymer with mainly alpha( 1->4) linkages and also alpha (1-> 6)  linkages

Oligosaccharides: few monosaccharides covalently linked
-covalently attached to proteins or membrane lipids  ( linear or branched chains)

Thursday, September 23, 2010

DNA replication

DNA Replication :
-existing DNA strands to serve as templates for new complementary strands
- Semiconservative, new DNA has 1 old 1 new strand

1, Helicase untwist and separate template DNA strands from the origin of replication, break hydrogen bonds and moves along the direction of leading strand
2, SS binding proteins keep the unpaired template strands apart during replication
3, Gyrase releases any tension brought about by the unwinding of the DNA strands
4, Primase attaches RNA primer as soon as there is a single strand
5, DNA polymerase 3 catalyze the elongation of new DNA and attaches free flowing nucleosides on to the single strand
6, Leading strand is replicated continuously towards replication fork while lagging strand is replicated in okazaki fragments. The growing direction of the new DNA strand is always 5 to 3. Therefore leading strand   always starts with 3 prime.
7, DNA polymerase 1 checks over the new replicated DNA strand and remove the RNA primer.
8, DNA ligase adds sugar phosphate backbone between the Okazaki fragments ( fill in gaps)

list of Enzymes
DNA polymerase 3
DNA polymerase 1
DNA ligase
helicase
gyrase
primase

Replication fork is where the parental DNA strands hasn't untwist. Replication bubbles allow DNA replication to speed up therefore the untwisted DNA would not be attacked by enzymes while replicating.

Sunday, September 19, 2010

5 famous geneticists

Kary Mullis (1944- present)
year of fame :1993
famous publication: invention of PCR( polymerase chain reaction)
Contributions: Polymerase Chain Reaction is used to amplify small pieces of DNA into thousands and millions copies of this certain piece of DNA. This technique is now used in the medical, biotechnology, forensic and genetic fields.

Rosalind Franklin(1920-1958)
year of fame: 1958 (after her death)
famous publication: Her work on the x-ray diffaction images of DNA. Her work was actually the data that brought Watson to his discovery of the Double Helix.
contributions: She was first to be able to see the X shape of the DNA ladder.

James D. Watson( 1928-)
year of fame: 1962
famous publication: Watson and Crick published their paper to the scientific journal Nature to reveal the true shape of DNA, the double helix.
contributions:
Watson along with Crick's help, discovered the form of DNA and the significance of the nucleic acids.

Frederick Sanger(1918 -)
year of fame: 1958
famous publication: Sanger method developed by Sanger was a technique to do DNA sequencing.
contributions: Sanger method is now widely used to determine the order of the nucleic acids. It is one of the most efficient and easiest method available for DNA sequencing.

Gregor Mendel (1822-1884)
time of fame: 20th century
famous publication: Experiments on Plant Hybrization was his work done to show dominant and recessive traits in inheritance.

contributions: He is known as the father of modern genetics. He is the first to begin the studies of the genetics field