3.2.5
Condensation: when two molecules become covalently bonded to each other throught the loss of a small molecule, usually water; also called the dehydration reaction.


external image CondensationReaction.jpg
Hydrolysis: A chemical prossess that splits molecules by the addition of water.
external image c8.8x13.hydrolysis.sucrose.jpg

  • In order for a monosaccharide to become a disaccharide, it must go through a condensation reaction. A condensation reaction must also take place when forming polysaccharides. And for a disaccharide to become a monosaccharide, a hydrolysis reaction must take place.

  • A triglyceride is formed by one molecule of glycerol and 3 fatty acids. In order for fatty acids and glycerol to bond together, a condensation reaction must take place.

  • When amino acids join together, they form polypeptide bonds through a condensation reaction.


3.3.1
DNA nucleotide is made up of 3 parts; phosphate, sugar and base
.
external image nucleotide.jpg




3.3.2
Adenine, Cytosine, Guanine, and Thymine
. (Purine: Adenine & Guanine. Pyrimidines: Thymine & Cytosine)

external image CG_ATGC.gif


3.3.3
Two nucleotides in DNA are linked together by a covalent bond with the sugar base of a nucleotide and the phosphate group of another. Nucleotides are added to form a single strand.

3.3.4
DNA molecules have two strands of nucleotides that are wound together forming a double helix. They are formed in between the bases of two strands. It is formed by complementary base pairing because the bases are selective and only have hydrogen bonds with only one other base. Adenine with Thymine and Cytosine with Guanine

3.3.5
external image moz-screenshot.jpgDNA.png



7.6.1 metabolic pathways are series of chemical reactions occurring within a cell. In each pathway, a principal chemical is modified by chemica reactions. Enzymes catalyze these reactions, and often require dietary minerals, vitamins, and other cofactors in order to function properly.
This collection of pathways is called the metabolic network. Pathways are important to the maintenance of homeostasis within an organism

external image metabolic-pathways.png
7.6.2
The favored model for the enzyme-substrate interaction is the induced fit model. This model proposes that the initial interaction between enzyme and substrate is relatively weak, but that these weak interactions rapidly induce conformational changes in the enzyme that strengthen binding.


7.6.3 external image Induced-fit_model.JPG
Like all catalysts, enzymes work by lowering the activation energy for a reaction, thus dramatically increasing the rate of the reaction. Most enzyme reaction rates are millions of times faster than those of comparable un-catalyzed reactions. As with all catalysts, enzymes are not consumed by the reactions they catalyze, nor do they alter the equilibrium of these reactions

7.6.4In competitive inhibition the substrate and inhibitor cannot bind to the enzyme at the same time, as shown in the figure on the left. This usually results from the inhibitor having an affinity for the active site of an enzyme where the substrate also binds; the substrate and inhibitor compete for access to the enzyme's active site.
poisons and drugs such as sarin


Non-competitive inhibition is a form of mixed inhibition where the binding of the inhibitor to the enzyme reduces its activity but does not affect the binding of substrate. As a result, the extent of inhibition depends only on the concentration of the inhibitor.
Oxalic and citric acid