Exam 1 Flashcards
structure of water
1 atom oxygen 2 atoms hydrogen H20 covalently linked polar molecule dipole moment
water
dipole moment
partially positive hydrogen
partially negative oxygen
water is liquid at room temp because of hydrogen bonds
why does surface tension happen
the interaction between the hydrogen bonds
ion solubility
ions are charged
hydrophilic
dissolves in water because of the interaction with the water
shell of hydration
the sodium ions have one with O facing them
the chloride ions will have one with the H facing them
because of the charges
diffusion across a barrier
know the randomness of diffusion across the barriers
know how we end up reaching equilibrium
know how things move from higher to lower concentration
osmosis
the water goes back and forth across channels called aquaporins until it reaches equilibrium
hydrophobic
uncharged
water fearing
triglycerides are an example
hydrophilic
charger
polar
water loving
Na+, Cl-, Ca2+ etc.
triglycerides
starts out with a 3 carbon structure glycerol which is the backbone of the triglyceride
to form a fatty acid there may be 16,18,20 carbons liinked to each other
uncharged
all of this then goes through dehydration synthesis
the H from the carboxylic acid and the OH from the glycerol go together to form a ester bond
does the same for all three
*highly insoluble in water
phospholipids as amphipathic molecules
- characteristics of a lipid which makes one portion hydrophobic
- start with a typical phospholipid with its 3 carbon backbone
- # 3 carbon creates a covalent bond, then take the oxygen and link it to O,P,O which is a phosphodiester bond–causes the end to be charged
phosphate head group
head is hydrophilic
tail is hydrophobic
short name for a phosphodiester bond
micelle
circle organization of phosphate head groups with their heads pointed outward and tails pointed inward
if water goes in the middle they will explode because the inside is hydrophobic and the outside is hydrophilic
not stable
liposome
same sort of structs as a micelle except there are two layers of phosphate head groups and the two layers of tails are pointing towards eachother making the whole molecule hydrophilic so there can be water in the middle and there can be water on the outside
stable
the inner layer is the phospholipid bilayer
lipid mosaic model of biological membranes
-has transmembrane proteins interspersed into the phospholipid bilayer that provide communication pathways for proteins
protein
- polymer of amino acids linked together by peptide bonds
- we create proteins from weaving them across the phospholipid bilayer
- to make sense we look at an amino acid
amino acid structure
- 20 different R-groups
- the term amino comes from the amino terminal on the left side and the carboxyl terminal on the right side
how to determine R-groups
- non-polar, uncharged, hydrophobic
- polar, hydrophilic
- charger, hydrophilic
peptide bonds
amino acid sequence: determines the primary structure sequence
the peptide bonds happen by amino acids strung together like pop beads on a string
primary structure of proteins
amino acid sequence
secondary structure of proteins
- derives from the hydrogen bonding of the protein
- do not require R-groups instead arise from hydrogen bonding within the protein
- hydrogen bonding occurs between the amine hydrogen and the carboxyl terminal
- creates two structure shapes
2 helix
- steps up a spiral staircase
- hydrogen bonding occurs every 4th on the way up the staircase
beta sheet
sheet like structure
tertiary structure of proteins
- when the proteins fold into geometric shapes with the hydrophobic on one side and the hydrophilic on the other side
- they fold in a way the the hydrophobic go on the inside away from the water and the hydrophilic go on the outside
- these form binding pockets which are a substrate for enzymes
- they need to be perfect in order to create these enzymes
transmembrane proteins
- the phospholipid bilayer when we thread a protein across it while following the hydrophilic and hydrophobic rules
- this region is configured as a helix
- there are hydrophobic amino acids that weave through the membrane which means there is a single alpha helix across the membrane
Hydrophilic pathway (channel)
- this is where we link 4 alpha helix across the membrane to form a channel across
- where some of the R-groups are pointed outward towards the other head groups and some inward
- the hydrophobic R-groups are pointed inward to form a hydrophilic pathway
prokaryotes
- bacteria, archaea
- lack intracellular membrane bound compartments
- obey the rules for DNA to RNA to protein
eukaryotes
- nucleus in the middle of the cell
- all DNA is confined to the nucleus
- each chromosome is a molecule of DNA
- there is a DNA binding protein called a histone
histone
- DNA binding protein
- form a spool where the DNA wraps
- organize into a set of 8 octomers
ribosomes
- used for proteins synthesis
- composed mostly of RNA
- factory to make proteins (mostly RNA)
- responsible for making synthesis of cytoplasmic proteins
- cytoplasmic structure
ER
-smooth ER
-rough ER with ribosomes attached to it
-free ribosomes
-membrane bound compartment inside the cell
-synthesize the three types of proteins:
secreted
lyposomal
transmembrane
**plastic bag example