ap bio notes
Fatty acids: Hydrocarbon chains with a carboxyl group at one end.
Glycerol: A three-carbon alcohol that serves as the backbone for triglycerides and phospholipids.
Ester linkage: A covalent bond formed between a carboxyl group ( -COOH ) and a hydroxyl group ( -OH ), typically found in fats and phospholipids.
Fat molecule (triglycerol): A lipid composed of three fatty acids linked to one glycerol molecule.
Saturated fat: A type of fat characterized by fatty acid chains that have no double bonds between carbon atoms, making them "saturated" with hydrogen atoms.
Unsaturated fat: A type of fat characterized by fatty acid chains that have one or more double bonds between carbon atoms, resulting in kinks in the chain.
Phospholipids: Lipids composed of a glycerol backbone, two fatty acid tails, and a phosphate group, forming the primary component of cell membranes.
Steroids: A class of lipids characterized by a four-ring structure, serving various functions in the body, including as hormones like cholesterol and testosterone.
Overview of protein functions:
Enzymatic proteins: Proteins that act as biological catalysts, speeding up specific biochemical reactions.
Storage proteins: Proteins that store amino acids or other substances for later use, e.g., ovalbumen in egg white.
Hormonal proteins: Proteins that act as chemical messengers, coordinating bodily activities, e.g., insulin.
Contractile and motor proteins: Proteins responsible for movement, such as actin and myosin in muscle contraction.
Defensin proteins: Proteins that play a role in the immune system, defending the body against pathogens.
Transport proteins: Proteins that facilitate the movement of substances across cell membranes or throughout the body.
Receptor proteins: Proteins that bind to specific signaling molecules, initiating cellular responses.
Structural proteins: Proteins that provide support and maintain the shape of cells, tissues, and organs, e.g., collagen.
There are 20 different amino acids.
These amino acids can be combined in various sequences to form proteins, which play crucial roles in cellular functions such as enzyme activity and immune responses. Additionally, proteins can serve as transport proteins, facilitating the movement of molecules across cell membranes and contributing to cellular communication.
Structure of amino acids: A central carbon bonded to an amino group ( -NH_2 ), a carboxyl group ( -COOH ), an R group (side chain), and a hydrogen atom. The unique properties of each amino acid are determined by the composition and arrangement of the R group, which influences the protein's shape and function. It is a variable group.
Non-polar amino acid examples: Amino acids with R groups that are primarily hydrocarbons and are hydrophobic (e.g., Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Phenylalanine, Tryptophan, Proline).
Polar amino acid example: Amino acids with R groups that have hydrophilic properties due to polar bonds (e.g., Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine).
Building proteins, polypeptide chains have directionality.
N-terminus: The end of a polypeptide chain with a free amino group.
C-terminus: The end of a polypeptide chain with a free carboxyl group.
Peptide bonds: Covalent bonds that link amino acids together in a polypeptide chain, formed by a dehydration reaction between the carboxyl group of one amino acid and the amino group of another.
Formed through peptide bonds
linking the of one amino acid to the of another
c-n bond
can only grow in the direction
primary structure: The unique linear sequence of amino acids in a polypeptide chain, determined by the genetic information in DNA.
Changing a single amino acid can alter the form and function.
Secondary structure: The regular, local folding patterns of the polypeptide chain, primarily helix and ext{beta}(\beta) -pleated sheet, formed by hydrogen bonding between the backbone atoms (carbonyl oxygen and amide hydrogen) of different amino acids, not involving R groups.
Tertiary structure: The overall three-dimensional shape of a single polypeptide chain, resulting from interactions between the R groups (side chains) of amino acids, anchored by disulfide bridges, hydrogen bonds, ionic bonds, and hydrophobic interactions.
Quaternary structure: The arrangement of multiple polypeptide chains (subunits) to form a functional protein complex, such as hemoglobin.
Denaturation of proteins:
-unfolding a protein
-disrupt 3 structure: pH, salt, temperature
-unravels or denatures protein
disrupts H bonds, ionic bonds, and disulfide bridges
destroys functionality
Some proteins can return to their functional shape after denaturation, but many cannot.
NUCLEIC ACIDS NOTES
function: store and transmit hereditary information
examples: RNA, DNA
Nucleotides:
nitrogen base (c-n ring)
pentose sugar (5C) ribose in rna, and deoxyribose in DNA
phosphate group (PO4) group
nucleic polymer
back bone has a sugar to -PO4 bond
phosphodiester bond - a new base is always added to the sugar of the previous base.
polymer grows in one direction
n bases hang off the sugar phosphate backbone
Pairing of nucleotides:
nucleotides bond between dna strands
h bonds
purine:: purimidine
a and t have 2 H bonds
G and C have a 3 H bond
ratio of a-t, and G-C affects the stability of dna molecule.
ATP, adenosine triphosphate,e its a nucleotide with a couple extra phosphate groups