Lecture 4 Flashcards
pH
measure of hydrogen ion concentration in a solution. Each pH unit represents a tenfold change in the concentration of H+
Alkalosis:
when there is a significant increase in physiological pH, alkaline/basic, causes include: excessive sweating or vomiting, poor oxygenation
acidosis:
when there is a significant decrease in physiological pH, acidic, causes include: lung and kidney disease mostly, unable to clear waste out from cells during exhale and urine formation, ketoacidosis specific to diabetic crisis.
Carbon Chemistry:
larger organic compounds-main molecules in the gasoline we burn in the cars and other machines- important fuels in our body. the energy rich parts of fat molecules have a structure similar to gasoline.
organic compounds
has a “carbon backbone”, versatile size, branching pattern bound to hydrogens (and oxygen)
why carbon?:
stability, versatility, 4 bonds, in our temperature range
Not all compounds with carbon are organic:
when it comes down to it, they also have “behave” organic. methane is organic, carbon dioxide is not
Functional groups:
organic compounds are basis of most chemical reactions in a cell. versatility in their carbon structure, versatility in their functional groups. Functional group is the part of an organic compound that is involved in a chemical reaction. Less stable than carbon backbone, react more readily with other molecules.
Hydroxyl:
polar, involved in dehydration and hydrolysis reactions, forms hydrogen bonds. found in sugars, polysaccharides, nucleic acids, alcohols, some amino acids, and steroids.
carbonyl:
polar, makes part of molecules hydrophilic (water soluble). found in sugars (linear forms), steroid hormones, peptides and proteins, some vitamins
Carboxyl (ionized form):
polar and acidic, the negatively charged oxygen may bond H+, forming carboxylic acid involved in peptide bonds. found in amino acids, fatty acids, carboxylic acids (such as acetic and citric acids)
Amino:
polar and basic, may become ionized by building a third H+, involved in peptide bonds. found in amino acids, nucleic acids, and some hormones
Sulfhydryl:
non polar, forms disulfide bonds in proteins. found in cysteine (an amino acid) and many proteins.
Phosphate (ionized form):
polar and acidic, links nucleotides in nucleic acids, forms high energy bonds in ATP (ionized form in cells)
Methyl:
non polar, may be attached to nucleotides in DNA (Methylation), changing gene expression. Found in steroids, methylated nucleotides in DNA
Macromolecules:
on a molecular scale, many of life’s molecules are gigantic, earning the name macromolecules
polymers vs monomers:
macromolecules are enormous, complex polymers. polymers are linked up monomers. think of a monomer like a building block- a brick is a single monomer in a wall, an amino acid id a monomer of protein, nucleotides are monomers of DNA
How do bodies make macromolecules:
start by piecing monomers together, not as simple as puzzle pieces. You need an enzyme- holds growing polymer and monomer in place, links them together. Dehydration reaction: removing water to put together. Monomers H+ and growing polymers OH-H2O. covalent bond formed between monomer and growing polymer
bonds can be broken through hydrolysis:
enzyme holds the polymer in place, uses energy to break covalent bond, adds -H onto one component and -OH on the other
carbohydrates:
hydrophilic (dissolve in water). in food: small sugar molecules in soft drinks and big starch molecules in spaghetti and bread. in animals: primary source of dietary energy (feeds glycolysis). raw material for manufacturing other kinds of organic compounds. In plants: primary source of dietary energy (feeds glycolysis) serve as building material for much of the plant body
small carbohydrates:
monosaccharides- monomers of larger carbohydrates, cannot be broken down into smaller sugars, common examples are glucose and fructose. monosaccharides )particularly glucose). are the main fuels for cellular work, in water, many monosaccharides form rings. Disaccharide: is a double sugar constructed from two monosaccharides by dehydration reaction. there’s an enzyme for that. include lactose in milk (glucose + galactose), maltose in beer (glucose +glucose), sucrose in table sugar (glucose +fructose)
large and complex carbohydrates:
polysaccharides-starch: plant cells used for energy, long strings of glucose monomers, different types of starch (amylose, amylopectin). Glycogen: animal muscle cells store this for energy, extensively branched glucose polymer, is broken down to release glucose when you need energy. cellulose: forms cable-like fibrils in the walls that enclose plant cells, cannot be broken by any enzyme produced by animals, is the most abundant organic compound on earth. chitin: exoskeletons in insects and invertebrates, cell wall of fungi
lipids:
oils/fats/waxes, phospholipids, steroids. Hydrophobic: unable to mix with water. because they are non polar, mostly composed of hydrocarbons, tiny or sparse polar functional groups. Fats/waxes/oils: fatty acid chains: long hydrocarbon (just carbon and hydrogen) with 1 carboxylic acid group. Glycerol: small (3 carbons) with hydroxyl (OH) groups. Triglyceride: 1 glycerol joined with three fatty acid chains. via a dehydration reaction (there’s an enzyme for that). energy storage: plants produce oils, animals produce fats (energy storage, cushioning, insulation) plants and animals produce wax
saturated vs unsaturated:
if all carbons in the fatty acid chains saturated with hydrogens= saturated. if not= unsaturated. Unsaturated: has double bonds between some of the carbon in the fatty acid chains, tends to be liquid at room temperature. Saturated: has no double bonds between carbon in the fatty acid chains, all three of its fatty acids saturated, tends to be solid at room temperature.
phospholipids:
unique properties of having a polar head and a non polar tails. make up plasma membranes of all cells. similar to triglycerides: 1 fatty acid chains replaced by phosphate group and functional group
lipid type steroids:
steroids are very different from fats in structure and function. The carbon skeleton has four fused rings. steroids vary in the functional groups attached to this set of rings, and these chemical variations affect their function. Cholesterol is a key component of cell membranes and the “base steroid” from which your body produces other steroids, such as estrogen and testosterone. cholesterol can be converted by the body into testosterone or a type of estrogen
proteins: there’s an enzyme for that:
instrumental in everything we do from movement to thinking: structural function: keratin (forms hair, nails, scales, feathers, and horns), silk (forms webs and cocoons) Movement function: actin and myosin (found in muscle cells; allows contraction) Defense function: antibodies (found in the bloodstream, fight disease organisms, some neutralize venoms), venoms (found in venomous animals, deter predators and disable prey) Storage function: albumin (in egg whites, provides nutrition for an embryo). signaling functions: insulin (secreted by the pancreas, promotes glucose uptake into cells) catalyzing reactions functions: amylase (found in saliva and the small intestine, digests carbohydrates). Proteins: composed of large chains of amino acids. protein =polymer. amino acid= monomer. they can be hydrophilic or hydrophobic It depends on their function.
amino acids:
all amino acids have these three things bound to the central carbon: a carboxyl group, an amino group, a hydrogen atom. That variable 4th component of amino acids. Side chain (R) (carbons). Unique
Peptide bonds are unique:
cells link amino acids together by dehydration reactions, forming peptide bonds. very stable. creating long chains of amino acids called peptides, polypeptides, proteins!
the overlapping terms of peptide, polypeptide, and protein:
peptide: at least 2 amino acids held together by peptide bonds. polypeptide: string ~20 amino acids. protein: 1 or more peptide chains (~100 amino acids). sweater analogy: the yarn is the peptide, the woven carefully into the shape of a sweater is a protein
4 levels of protein structure:
primary structure: the sequence of amino acids is linked peptide bonds. secondary structure (helix): this is maintained by hydrogen bonds. tertiary structure: folding of the helix results from hydrogen bonds with surrounding water molecules and disulfide bridges between cysteine amino acids. Quaternary: individual polypeptides are linked to one another by hydrogen bonds or disulfide bridges.
