Chapter TWO. Biochemistry Flashcards
Inorganic compounds
Lack carbon and are structurally simple
ex. water, salts, acids and bases
Organic compounds
always contain carbon (usually hydrogen). are formed by covalent bond (ex. carbohydrates, lipids, proteins, nucleic acids, and adenosine triphosphate/ATP)
Water
Most abundant and important inorganic compounds i all living organisms
Water
Most abundant and important inorganic compounds in all living organisms
Important properties in water
- high heat capacity
- high heat of vaporization
- polar solvent (water can dissolve most things) (holds ionic and covalent bonds)
- formed during dehydration synthesis reactions and required in hydrolysis reactions
- cushioning and lubricating effect
Salts
Dissociate into positive and negative ions (neither of which is H+ or OH-) when dissolved in water
Acids
Dissociate into 1 or more hydrogen ions (H+), and 1 or more negative ions.
(Also known as proton donors)
Bases
Dissociate into 1 or more hydroxyl ions (OH-) and 1 or more positive ions.
(Also known as proton acceptors)
The pH Scale
number from 0-14
- pH greater than 7 is acidic
- pH less than 7 is basic
- pH = to 7 is neutral
1 pH unit = to a 10X change in H+ concentration
ex. pH of 6 has 100X more H+ than the pH of 8
Organic Compounds
- comprise 38-40% of total body mass.
- contain Carbon, Hydrogen, and other functional groups
- are built by joining monomers (small building blocks) together into polymers (macromolecules).
ex. Lego blocks (building blocks)
Carbon
- Atomic number = 6
- has 4 valence shell electrons so usually forms 4 covalent bonds with other elements
Dehydration Synthesis
Monomers are joined by removal of OH from one monomer and removal of H from the other at the site of bond formation. (This allows them to share electrons to form a covalent bond)
Hydrolysis
Monomers are released by the addition of water molecule, adding OH to one monomer and H to the other (AKA chemical breakdown of molecules due to water)
Carbohydrates
- includes sugars, glycogen, starches, and cellulose
- composed of C, H, and O
- Are the main source of chemical energy for metabolism
Monosaccharides
simples, with general formula CH2O ex. glucose
Disaccharides
formed by a dehydration synthesis to join 2 monosaccs ex. sucrose
Polysaccharides
large chains of many monosaccs joined together. ex. glycogen
Isomers
Glucose, Fructose, Galactose
Lipids
are Hydrophobic (water-fearing)
- composed of C, H, and O (but less O)
- nonpolar compounds (no soluble in water
- includes Triglycerides (fats and oils), phospholipids, and steroids
Triglycerides (neutral fats)
- composed of glycerol and 3 fatty acid chains
- important for storage of energy, insulation, and shock absorption
Phospholipids
- composed of glycerol, 2 fatty acids, and a phosphate group (polar)
- main component of membranes
- (hydrophilic - water loving)
Steroids
- consists of 4 interlocking carbon rings with various side groups
- includes cholesterol and steroid hormones
Proteins
- composed of C, H, O, and N (can also have sulfur and phosphorous)
- are polymers built from the 20 different amino acids
Amino acids
are joined by peptide bonds (covalent bond) formed by dehydration synthesis
Protein Structure (4 structural levels of proteins)
- Primary structure: Linear sequence
- Secondary structure: a-helix or B-pleated sheet
- Tertiary structure: complex globular shape. (three-dimensional shape of polypeptide chain)
- Quaternary structure: interaction of 2 or more polypeptides (arrangement of two or more polypeptide chains)
How are proteins classified?
Structural (fibrous) or Functional (globular)
Structural (fibrous)
- stable and insoluble in water
- provide mechanical support and give strength
Functional (globular)
- less stable, H-bonds break easily
- are water soluble
what happens to proteins if their environment changes
can denature and ceese to function
Catalysts
Substance that increases weight of chemical reaction without being used up or altered in any way
Nucleic Acids (large molecule)
- Composed of C, H, O, N, and P
- are chains of nucleotides (long chains of building blocks/monomers)
Nucleotide
Nucleotide = phosphate group + 5C sugar (pentose) + nitrogenous base
Two kinds of Nucleic acids
- Deoxyribonucleic acid (DNA)
- Ribonucleic acid (RNA)
Deoxyribonucleic acid (DNA)
- double stranded polymer (ladder-like-shape), twisted into a double helix
- sugar is deoxyribose
- N-bases are A, T, C, and G
- H bonds join N-bases (“rungs”)
- alternating sugar and phosphate molecules form the “uprights” of the ladder
Ribonucleic acid (RNA)
- single nucleotide chain
- sugar is ribose
- N-bases are A, U, C, G (U replaces the T found in DNA)
Several types of RNA (3)
rRNA, mRNA, tRNA (all involved in protein synthesis)
