Biological Molecules
Lipids
Proteins
Carbohydrates
Nucleic Acid
there are 20 different amino acids commonly found in living things
Proteins can be made up of one or more polypeptides giving them a wide range of forms
Made up of amino acid chains- polymers of amino acids called polypeptides
disaccharide- two monomers connected by a dehydration reaction
simple sugars or complex sugars (polymers)
monosaccharide- one ring
Phospholipids
fused ring
Oils, Fats Waxes
Each nucleotide contains: 5-C sugar-either Ribose or deoxyribose (has one less oxygen), phosphate group, nitrogen-containing base- adenine (2-ring), guanine (2-ring), cytosine (1-ring) or thymine (1-ring)
In DNA: the phosphate group of one nucleotide is covalently bound to the sugar of another
Made up of long chains of nucleotides -contain N and P (in addition to C, H, O
C, H, O - 1:2:1 ration
contain hydroxyl group (functional group) making them polar
Short term energy storage
Quick energy from hydrolysis of monosaccharides
polysaccharides function as storage or structural molecules
Contain fatty acid subunits- long chains of C and H with a carboxyl group at one end
Fats and oils are triglycerides- 3 fatty acid subunits and 1 glyerol
Conatin C, H, and O
Most fats- animals- saturated (no double bonds with hydrocarbons)
Most oils- plant seeds- unsaturated (at least one double bond with hydrocarbons) *double bonds cause "kinks" keeping them liquid at room temperature
Hydrogenated oils (trans fats) created by breaking fatty acid double bonds- our bodies are unsure of how to "deal" with these molecules and the trans fats can lead to an increase in bad cholesterol
Waxes are not a food source- we don't have the enzymes to break them dow
One end is nonpolar because of fatty acid chains
Other end is polar because of phosphate - nitrogen group
Similar to oils, but have a phosphate group
Major component of cell membrane
Only 2 fatty acid chains- fats have 3
Cholesterol is a type of steroid
4 fused rings of carbon with different functional groups - steroids
Joined with ester bonds- glycerol molecule and 3 fatty acid molecules by dehydration synthesis
Peptide bond- connects the amino group of one amino acid and the carboxyl group of another
2-50 amino acids linked together: dipeptide
Four Levels to Organization
50+ amino acids: polypeptide or protein
Hydrogen bonds hold bases together
Functions:
DNA- Sequence of nucleotides is different in every species=unique code to synthesize proteins (made up of 2 nucleotide chains that twist to form a "double helix"
RNA- copies of DNA, carries genetic code from nucleus to cytoplasm so that it can be read/ proteins can be synthesized
Cyclic AMP- intracellular messengers that carry chemical signals
ATP transports energy within cells, product of cellular respiration
2) Secondary Structure- Formed by hydrogen bonds between the amino and carboxyl group of amino acids
3) Tertiary Structure- complex 3-D structure determined by cellular environment, disulfide bridges can contribute to structure, form when 2 cysteines bond together
1) primary structure- sequence of amino acids (determined by DNA) (peptide bond)
4) Quaternary structure -in some proteins individual polypeptide chains are linked together
(alpha) helix structure- caused by hydrogen bonds that form betwee Co of hydroxyl groups and hydrogen in NH groups of same peptide
(Beta) pleated sheet- repeated folds form when a peptide folds on itself and hydrogen bonds form
Structure and Function
Denaturation- occurs when the 2 and 3 structures of a protein have been altered, protein cant function properly
Determined by DNA- amino acids must be in proper sequence in order to be in the correct place in a protein
Proteins can be denatured by: changes in temp, changes in salinity, changes in pH