Module 2 - Anatomy Flashcards
ionic bond
attraction between oppositely charged ions: cation (+) and anion (-)
covalent
the sharing of a pair of valence electrons by 2 atoms
1) non-polar: electrons equally shared
2) polar: electrons shared unequally
hydrogen bonds
attraction between partially positively charged hydrogen atoms and partially negatively charged electronegative atoms
macromolecules
1) carbohydrates
2) proteins
3) lipids
4) nucleic acids
Macromolecules
- they are all organic
- mostly CHO atoms
- High carbon content
why carbon?
- common
- 4 valence electrons
- bonds to other carbons to form complex backbones
- forms covalent bonds
reactions to make and break polymers
1) dehydration synthesis/condensation
2) hydrolysis
dehydration synthesis/condensation
1+1=2
product: water + polymer
hydrolysis
2=1+1
reactant: water + polymer
carbohydrates: function
- carbohydrates are a quickly mobilized source of energy
- all digested carbohydrates converted to glucose
- oxidized to make ATP
- carbohydrates are often conjugated with:
1) lipids -> glycolipids
2) proteins -> glycoproteins - proteoglycans are more carbohydrate than protein
1) gels that hold cells and tissues together; fill the umbilical cord and eye
2) joint lubrication: responsible for the rubbery texture of cartilage
Phospholipids
Amphipathic
- hydrophilic heads
- hydrophobic tail
eicosanoids
- function primarily as chemical signals between cells (cellular communication)
- prostaglandins: inflammation, pain, blood clotting
steroids
- lipids in which the carbon skeleton contains 4 fused rings
- cholesterol = 4 ring parent steroid
1) importance structural component of cellular membranes
2) starting material for making steroid hormones (communication): cortisol, testosterone, estrogen
amino acid
central carbon bonding with
1) an amino group
2) a carboxyl group
3) a hydrogen atom
4) a functional group R
classified as:
- hydrophilic
- hydrophobic
dipeptide
proteins are made from amino acids linked by peptide bonds
polypeptide
peptides are names for the number of amino acids they contain:
- dipeptides (2 amino acids)
- tripeptides (3 amino acids)
- oligopeptides (btwn 3 and 15 amino acids)
- polypeptides btwn 15 and 50 amino acids)
- proteins (more than 50 amino acids)
primary structure
- the unique linear sequence of amino acid that determines all other levels of structure
- results from the formation of peptide bonds between amino acids
Secondary structure
- the two dimensional shape: the coiling (alpha helix) or folding (beta-pleated sheet) of the polypeptide
- results from the formation of hydrogen bonds between atoms of the polypeptide backbone
Tertiary structure
- the three-dimensional shape
- results from interactions between the R groups of the various amino acids (disulfide bridges)
Quaternary structure
- the association of 2 or more polypeptide chains
- results from ionic bonds and hydrophobic interactions
enzymes
- proteins
- biological catalysts
- lower activation energy of reactions
- increase the rate of a reaction without being consumed by the reaction (neither reactants nor products)
- highly specific
enzyme proteins
serve as metabolic catalysts and regulate chemicals
structural proteins
provide associations between body parts
contractile proteins
are found within muscles