Transcript biochemistry-micromolecules

Organic vs. Inorganic

All compounds can be separated into two
groups:

Inorganic
• Doesn’t contain carbon
• Non-living
• Examples: Oxygen gas, metals, rocks, water

Organic
• Contains carbon
• Living (or dead)
• Examples: wood, grass, diamonds, petroleum
1
Polymerization



Monomers
 One unit of a compound
Polymers
 Many monomers combine to make a polymer
Macromolecules
 Many large molecules combined
2
Carbohydrates


Made of C, H, O
Functions



Main energy source in organisms
Structural component in plants (CELLULOSE)
Types

Sugars
• gives off energy when broken down
• Ex. Sucrose, fructose, glucose

Starches
• used as a storage molecule for sugars
• Ex. Bread, rice, pasta, corn
3
Lipids

Made of C, H, O



Commonly called fats, oils, waxes
Functions






in the form of glycerol and fatty acid chains
Storage of energy
Parts of biological membranes
Water proof coverings
Chemical messengers (steroids)
Insoluble in water
Ex. Lard, butter, oil, hormones, steroids
4
Fatty acid
Figure 3.8B
Figure 3.8C
 Saturated
 They
fats (lard) lack double bonds
are solid at room temperature
5
Nucleic acids


Made of C, H, O, N, P
Monomers are called
nucleotides


Functions



Nucleotides are made up of a
5-carbon sugar, phosphate
group and a nitrogen base
Store hereditary information
Transmit hereditary
information
Nitrogenous
base (A)
Phosphate
group
Sugar
Figure 3.20A
Two types


RNA (ribonucleic acid)
DNA (deoxyribonucleic acid)
6
RNA vs DNA

There are THREE main differences between DNA
& RNA

The sugar
• In DNA its DEOXYribose sugar
• In RNA it’s Ribose sugar

Number of strands
• DNA is usually double stranded
• RNA is ONLY single stranded

Nitrogen Bases
• DNA
• Adenine pairs with Thymine
• Guanine pairs with Cytosine
• RNA
• Adenine pairs with Uracil
• Guanine pairs with Cytosine
7
Proteins


Made of C, H, O, N (P, S)
Monomers are amino acids



There are 20 different amino acids
that combine in different ways to
make millions of proteins
The most diverse macromolecules
Functions





Control the rates of chemical
reactions (enzymes)
Regulate cell processes
Used to form bone & muscles
Transport substances into or out of
cells
Help fight disease
Amino
group
Carboxyl (acid)
group
Figure 3.12A
8
Primary
structure
Amino acid
Hydrogen
bond
Secondary
structure
Pleated sheet
Alpha helix
Figure 3.15, 16
Tertiary
structure
Polypeptide
(single subunit
of transthyretin)
Quaternary
structure
Transthyretin, with four
identical polypeptide subunits
Figure 3.17, 18
9
Enzymes


Special PROTEINS
Act as biological CATALYSTS:
 speed up the rate of a chemical reaction by lowering
the activation energy of the reaction
 Activation Energy: energy needed to transform
reactant substances into product substances
Reaction pathway
without enzyme
Reactants
Reaction pathway
with enzyme
Activation energy
without enzyme
Activation
energy
with enzyme
Products
10
• Enzymes are specific in the reactions they
catalyze (Lock and Key model)
• They will only catalyze one specific substance, in one
direction (a -> b, but not b -> a)
• They are reusable
• A substance that an enzyme reacts on is called the
enzyme’s substrate
• Only the active site in the enzyme actually binds to
the substrate
• Enzymes end in –ase
• Example: amylase, helicase
11
Factors Affecting Enzyme Activity:
• PH
• Temperature
• Salt concentration
• Enzymes lose their shape easily
(denature)
• Shape is very important in
enzyme activity!
12