Notes – Biochemistry
Matter – anything that has weight and takes up space
Element – substances consisting of the same type of atom
Atomic Structure
Nucleus – protons + neutrons
Electrons
Atomic number – number of protons in the nucleus
Atomic weight – number of protons + the number of neutron in the nucleus
Isotope - Atoms of an element that have differing numbers of neutrons (but a constant
atomic number.
Bonds
Ionic bonds are formed when atoms become ions (electrically charged atoms) by gaining
or losing electrons.
Covalent bonds are formed when atoms share electrons.
Molecules – two or more covalently bonded atoms
Polar covalent bond (water) occurs when one pole of the molecule is more negative that
the other
Single covalent bond – one pair of electrons is shared
Double covalent bond – two pairs of electrons are shared
Hydrogen bonds - result from the weak electrical attraction between the positive end of
one molecule and the negative end of another
Compounds – formed from the combination of atoms of different elements
Molecular formula – symbols of the elements with a number to indicate how many
atoms of each element are present C6H12O6
Chemical reactions
Synthesis Exchange Reversible
Decomposistion
A + B > AB
AB + CD > AD + CB
A + B AB
AB > A + B
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Electrolytes – substances that release ions in water (ionize); these ions will conduct
electricity
Acids – electrolytes that release more H ions than OHBases – electrolytes that release more OH- than H+
Biochemistry:
Anabolism is the total series of chemical reactions involved in synthesis of organic
compounds.
Catabolism is the series of chemical reactions that breakdown larger molecules. Energy
is released this way, some of it can be utilized for anabolism. Products of catabolism can
be reassembled by anabolic processes into new anabolic molecules.
Organic: derived from living things and contain carbon and hydrogen
inorganic compounds: generally derived from non living things and does not contain
carbon and hydrogen
Water: H2O – inorganic, polar compound therefore an effective solvent, most
abundant substance on earth, adhesion of water ( attraction of water molecules to solid
surfaces) gives it the property of capillary – the ability to spread through fine pores or
move upward through narrow tubes against the force of gravity
Condensation ( dihydration synthesis); reactants give up a H and an OH to form
water as a product.
Hydrolysis: a water molecule splits a compound apart and H goes with one
monomer and an OH goes with the other monomer.
Organic compounds:
1. Carbohydrates:– building blocks are monosaccharides
a. monosaccharides (simple sugar) - glucose, C6 H12 O6, fructose,
galactose; ribose, deoxyribose
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b. disaccharides (double sugar) C12 H22 011 – sucrose, lactose; formed
by dehydration synthesis of two monosaccharides
c. polysaccharides plant starch or glycogen in animals (found in muscles
and liver): used for energy; if not used immediately then stored as
glycogen or fat.
2. Lipids: insoluble on water but are soluble in certain organic solvents; C,H,O;
a. Neutral fats - triglycerides (fats – solid oil - liquid), building blocks
are fatty acids and glycerol; most abundant and concentrated source of
usable energy; saturated fats – single carbon-carbon bonds bound to
as many H atoms as possible, solid at room temperature; unsaturated
fats- contain at least one double bond, liquid at room temperature;
polyunsaturated fats – contain many double bonds; artherosclerosis –
deposit of fatty substances on the artery walls can lead to
arteriosclerosis – hardening of the arteries
b. Phospholipids: similar to neutral fats except they contain phosphorus
which carries and electrical charge; compose the cell membrane –
hydrophobic (fatty acid tails) and hydrophilic (phosphate heads);;
c. Steroids: steroids considered a lipid because they do not dissolve in
water, composed of four carbon rings; most important steroid is
cholesterol because it is the raw material used to form some hormones
(sex hormones and cortisol), vitamin D and bile salts;
3. Proteins: H, C, O, N; building blocks are amino acids (20 different types);
a .amino acids contain an amine group NH2
b. peptide bond – covalent bond between a N atom and a C atom
a. dipeptide- two amino acids bonded together;
b. polypeptide – long chain of amino acids; used for building,
receptors, energy and enzymes
d. protein types
a. structural proteins – fibrous proteins – bind structures together
ex. Collagen and keratin
b. globular proteins – functional proteins, antibodies, hormones,
enzymes. enzymes – proteins that act as catalysts in
intermediary metabolism, speeds up the chemical reaction by
lowering the activation energy; functioning of the enzyme
determined by shape of protein; active site within which the
specific substrate(s) will "fit"; lock and key – enzyme
/substrate complex; recognizes, confines and orients the
substrate in a particular direction. Coenzymes- nonprotein
organic molecules bound to enzymes near the active site.; -ase
signifies an enzyme
4. Nucleic Acids: building blocks are nucleotides
a. RNA and DNA, control cellular activities;–
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b. consists of a five carbon sugar (ribose or deoxyribose) a phosphate group
and organic bases (adenine, guanine, thymine, cytosine, uracil)
c. DNA double helix; RNA single strand
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