Macromolecules
Proteins
Proteins are the essential macromolecule in the organs and soft structures within human and animal bodies.
Proteins have low molecular weight.
Proteins are amino acids binded together by a carboxyl group to another.
Proteins can either have a primary structure, secondary structure, tertiary structure or quaternary structure.
The function of a protein depends on it's shape.
Carbohydrates
Carbohydrates provide energy for living creatures.
Consists of only the elements carbon, oxygen and hydrogen.
Exmaples: Glucose, fructose and galactose.
Lipids
Three types of lipids: Fat, phospholipids and steriods.
Functions: Energy storage, membrane structure, hormones, insulation and digestion.
Saturated: Packed very tightly together, contain single covalent bonds between carbons and the chain of fat is saturated with hydrogen.
Unsaturated: Increased fluidity, not packed as tightly as saturated fats, monounsaturated fats have one double bond and polyunsaturated fats have more than one double bond.
DNA
Made up of nitrogenous bases, a sugar and a phosphate group.
Four different nitrogenous bases: adanine, cytosine, guanine, thymine.
DNA contains genetic material necessary for DNA replication, transcription, translation and inheritance.
Sunday, October 31, 2010
DNA Replication
DNA Replication
Enzymes Involved:
Gyrase: Releases pressure from the DNA during the unwinding of the double helix.
Helicase: Unwinds the double helix by breaking the hydrogen bonds.
Single-Stranded binding proteins: Prevents the DNA from reforming their hydrogen bonds and twisting back into their double helical structure.
Primase: Lays down primers indicating the starting point of replication.
DNA Polymerase 3: Builds the new DNA sequence by attaching corresponding nucleotides. Builds from 5' -> 3'
DNA Polymerase 1: Removes primers and checks for incorrect DNA sequencing and corrects the mistake (s).
Ligase: Joins Oakzaki fragments with a phosphodiester bond.
1. Gyrase allows the double helix to be unwound without tension.
2. Helicase unwinds the double helix which makes an unzipped helix.
3. Single-stranded binding proteins hold the strands apart to prevent the helix from joining back together again.
4. Primase lays down primers to indicate the starting position for replication.
5. DNA polymerase 3 adds the corresponding nucleotides to the strands of DNA; they add in the direction of 5' to 3'.
The leading strand is the strand that is built continuously towards the replication fork. The lagging strand is the strand built away from the replication forks in fragments, known as Okazaki fragments.
6. DNA polymerase 1 removes the RNA primers and double checks the sequence that was made.
7. DNA ligase joins gaps between each Okazaki fragment.
Enzymes Involved:
Gyrase: Releases pressure from the DNA during the unwinding of the double helix.
Helicase: Unwinds the double helix by breaking the hydrogen bonds.
Single-Stranded binding proteins: Prevents the DNA from reforming their hydrogen bonds and twisting back into their double helical structure.
Primase: Lays down primers indicating the starting point of replication.
DNA Polymerase 3: Builds the new DNA sequence by attaching corresponding nucleotides. Builds from 5' -> 3'
DNA Polymerase 1: Removes primers and checks for incorrect DNA sequencing and corrects the mistake (s).
Ligase: Joins Oakzaki fragments with a phosphodiester bond.
1. Gyrase allows the double helix to be unwound without tension.
2. Helicase unwinds the double helix which makes an unzipped helix.
3. Single-stranded binding proteins hold the strands apart to prevent the helix from joining back together again.
4. Primase lays down primers to indicate the starting position for replication.
5. DNA polymerase 3 adds the corresponding nucleotides to the strands of DNA; they add in the direction of 5' to 3'.
The leading strand is the strand that is built continuously towards the replication fork. The lagging strand is the strand built away from the replication forks in fragments, known as Okazaki fragments.
6. DNA polymerase 1 removes the RNA primers and double checks the sequence that was made.
7. DNA ligase joins gaps between each Okazaki fragment.
Subscribe to:
Posts (Atom)