The Structure and Function of Large Biological Molecules: Chp 5 Flashcards
polymers
long chain molecules made of repeating subunits called monomers EX: starch is a polymer composed of glucose molecules. EX2: proteins are polymers composed of amino acid monomers
dehydration reactions
create polymrs from monomers. two monomers are joined by removing one molecule of water
hydrolysis
occurs when water is added to split large molecules. this occurs in the reverse of dehydration reaction
carbohydrates
include both simple sugars (glucose, fructose, galactose) and polymers such as starch made from these and other subunits. . All carbohydrates exist in a ratio of 1 carbon: 2 hydrogen: 1 oxygen
monosaccharides
the monomers of carbohydrates. EX: glucose and ribose
polysaccharides
polymers of monosaccharides EX: starch, cellulose, and glycogen
functions of polysaccharides
energy storage and structural support
energy-storage polysaccharides
- starch is a storage polysaccharide found in plants
- glycogen is a storage polysaccharide found in animals, vertebrate muscle cells, and liver cells
structural-support polysaccharides
- cellulose is a majorcomponent of plant cell walls
- chitin is found in the exoskeleton of arthropods, such as lobsters and insects and the cell walls of fungi. It gives cockroaches their “crunch”
what type of molecules are lipids
they are hydrophobic. they are also NOT polyermes because they are assembled from a variety of components
what are fats made up of
a glycerol molecule and three fatty acid molecules
what are fatty acids composed of
hydrocarbon chains of variable lengths. the chains are nonpolar and therefore hydrophobic
characteristics of saturated fatty acids
-have no double bonds between carbons
-tend to pack solidly at room temperature
-are linked to cardiovascular disease
-are commonly produced by animals
EX: butter and lard
characteristics of unsaturated fatty acids
-have some carbond double bond that results in kinks
-tend to be liquid at room temperature
-commonly produced by plants
EX: corn oil and olive oil
functions of lipids
- energy storage (fats store twice as many calories/grams as carbs)
- protection of vital orans and insulation
characteristics of phospholipids
- have a glycerol backbond (head), which is hydrophilic
- have two fatty acid tails, which are hydrophobic
- are arranged in a bilayer in forming the cell membrane, with the hydrophilic heads pointing toward the watery cytosol of extracellular environment, and hydrophobic tails sandwiched in between
steroids
made up of four rings that are fused together
cholesterol
a steroid. It is a common component of cell membranes
estrogen
steroid hormone
testosterone
steroid hormone
proteins
polymers made up of amino acid monomers
amino acids
contain a central carbon bonded to a carboxyl group, an amino group, a hydrogen atom, and an R group
peptide bonds
link amino acids. formed by dehydration synthesis
four levels of protein structure
primary structure is the unique sequence in which amino acids are joined. Secondary structure refers to one of two three-dimensional shapes that are the result of hydrogen bonding. Alpha helix are coiled shapes that appear like a slinky. Beta pleated sheets are accordion shaped. Tertiary structure results in a complex globular shape, due to interactions between R groups, such as hydrophobic interactions, van der waals interactions, hydrogen bonds, and disulfide bridges. globular proteins such as enzymes are held in position by the R group interactions. Quaternary structure refers to the association of two or more poly peptide chains into one large protein. Hemoglobin is a globular protein with quaternary structure, as it is composed of four chains.
