Transcript biochem for genetics ppt

Genetics and Biotechnology
Biochemistry Notes
Organic compounds:
Contain carbon
Originally from living or once living
things
In addition to carbon, most contain
Hydrogen and oxygen
Other elements include:
Nitrogen
Sulfur
Phosphorus
Iron
Calcium, sodium, chlorine, magnesium,
potassium
Inorganic compounds:
Do NOT contain carbon
CO2 and carbonate compounds,
although found in living things, are not
considered organic.
Water:
Most important inorganic compound
in living things
Ionic bonds:
Transfer of electrons
Covalent bonds:
Share electrons
Polar covalent bonds:
Electrons “shared” unequally due to
electro negativity of an atom
Hydrogen Bonds:
Formed between hydrogen in one
molecule and an electro-negative
molecule in another
1/10th strength of covalent bond
Very important in interactions of biomolecules
Primary force in way proteins fold and DNA bases
bond
Structure & types of organic
compounds.
Major difference between organic and
inorganic compounds
Greater size and complexity because of
carbon’s electron structure
Carbohydrates:
Main source of energy
Made of elements
carbon, hydrogen, oxygen
ratio of hydrogen to oxygen is 2 to 1, like
water H2O
example: C6H12O6 common
monosaccharides
Many types of carbohydrates:
Sugars: names of sugars end in ~ose
(glucose, fructose, dextrose)
Monosaccharides : simple sugars
C6H12O6 or C5H10O5
Monomer: small repeating unit that
makes up a polymer, monosaccharide
or amino acid
Polymer: large molecule made up of
many small repeating units
Dehydration synthesis
A reaction in which two molecules are
bonded together by the removal of a
water molecule
dehydration: removing water
synthesis: put together
formation of a disaccharide:
Hydrolysis:
Process by which large molecules are
broken apart by the addition of water
molecules (requires enzymes, too)
Hydro: water
Lysis: break down or apart
Disaccharides:
Formed by joining two simple sugars
Sucrose or table sugar is a disaccharide made of
glucose and fructose
Lactose, a sugar found in milk, is made of glucose
and galactose
Lactose intolerant: inability to digest,
hydrolyze, lactose into galactose and
glucose; not enough of the enzyme lactase
Polysaccharides:
Polymer of many repeating sugar units
Starch: sugar is stored in plants as starch;
found in seeds, roots, and stems
Glycogen: surplus sugar stored in the liver
Cellulose: found in plants,
humans cannot digest cellulose—called
fiber
some animals, like rabbits, can digest
cellulose using appendix
Lipids:
includes fats, oils, waxes
Made of carbon, hydrogen, oxygen
like carbohydrates, however, much
less oxygen
insoluble in water – hydrophobic,
“water fearing”
Triglycerides:
Nutritionally and medically important
Energy storage
Oils: liquid at room temperature; come from
Plants: corn oil, olive oil
Fats: solid to semisolid at room temp; from
animals store fat: prevents heat loss; cushions
certain organs
Saturated and unsaturated fats:
Saturated: all carbon to carbon bonds are
single bonds
Unsaturated: one or more carbon pairs
are joined by a double or triple bond
c-c-c-c-c-c-c-c
c=c-c-c-c-
polyunsaturated: more than one double or
triple bond
Hydrogenated: process used to turn
unsaturated fats into saturated fats
Phospholipids:
Found primarily in cell membrane
Head---hydrophyllic—literally
water loving
Tail—hydrophobic—water
fearing
Steroids:
Composed of three 6-carbon rings
bound to a 5-carbon ring
Hormones, venoms, pigments
cholesterol:
Soft, waxy fat found in cell membrane
Part of some hormones
Too much cholesterol can contribute
to cardiovascular disease
Proteins
made of the elements carbon,
hydrogen, and oxygen like
carbohydrates and lipids, but also
contain nitrogen and sometimes sulfur
and phosphorous
Proteins perform many jobs
Structural-ex. Collagen (part of bone)
Enzyme-ex. Lactase
Transport-ex. hemoglobin
Contractile-ex. myosin-muscle contraction
Hormone-ex. Insulin
Antibody-ex. gamma globulin
Pigment-ex. Melanin
Recognition- ex. Cell surface
Toxins- ex. Botulism toxin (botox)
Protein are made of amino acids
20 amino acids, but they combine to form
1000’s of proteins
Two amino acids combine with a special
bond called a peptide bond
The resulting molecule is called a dipeptide
A chain of amino acids connected by
peptide bonds is called a polypeptide
Proteins are made of one or more of these
polypeptides, containing anywhere from 50
to 100,000 amino acids.
Structure of proteins
Primary: the “strand” of amino acids
Secondary: the chain of amino acids
twists or bends to form a more
complex structure, usually a coil or a
“pleat”
Tertiary: the coil or pleat fold to make
a ball
Quaternary: two or more chains fold
together
Nucleic Acids
Made of carbon, hydrogen, oxygen,
phosphorous, and nitrogen
Two kinds
DNA or deoxyribonucleic acid
Hereditary material passed from one
generation to the next
Genes: sequence of nucleotides of DNA that
codes for a particular polypeptide
RNA or ribonucleic acid
Three kinds: rRNA, tRNA and mRNA
RNA is very important
Necessary to “unlock” DNA
Necessary to make proteins
Structure of nucleic acids
A backbone of 5 carbon sugars
(ribose or deoxyribose) bonded to a
phosphate group (PO4)
Attached to one of four nitorgenous
bases: adenine, guanine, cytosine,or
thymine (uracil in RNA)
In DNA there are two backbones and
the bases align with each other
The “ladder” coils into the familiar
double helix