The four Macromolecules Flashcards
six major groups of lipids are :
fatty acids triacylglycerides phospholipids glycolipids steroids terpenes
fatty acids are the __ for most lipids
building blocks !
they are long chans of carbons and have carboxylic acid on one end.
they can be saturated or unsaturated.
saturated fatty acids have …
single C-C bonds
unsaturated Fatty acids have…
one or more carbon -carbon double bonds
triglycerides have ?
3 carbon backbone called gluycerol which is att to 3 FA’s
they store energy
adipocytes have cytoplasms full of triglycerides
phospholipids are made of?
glycerol backbone as well but a polar phosphate group will replace one of the FA’s
phosphate group lies on the opp side of the glycerol from the fatty acids making the phospholipid polar at the phosphate end and non polar at the fatty acid end.
these are amphipathic
glycolipids have ?
one or more carbs attatched to the 3 C glycerol backbone. these are also amphipathic . they are found in abundance in membranes of myelinated cells in nervous system
steroids are made of?
four ring structure. they include some hormones , vitamin D, and cholesterol.
terpens include ?
vitamin A , which is important for vision.
what are eicosanoids ?
they are 20 carbon length long. they include prostaglandins , thromboxjnes.
these are released from the cell mem as local hormones that regulate among other things, BP, body temp, and smooth muscle contractions.
how are lipids transported in the blood?
via lipoproteins ! - which has a lipid core surrounded by phospholipids. it dissolves lipids in the hydrophobic core, and moves free in aqueous solution due to its hydrophilic shell. liporproteins are classified by their density.
proteins are made form chains of aa linked together by
peptide bonds.
how many amino acids are essential
10 ! - body can’t make these 10
what are the non polar amino acids?
GAPVLIMPT G- glycine A: alanine P: proline V: valine L: leucine I : isoleucine M: methionine P : Phenylalanine T: tryptophan
what are the polar aa?
SAGTTC S: SERINE A: ASPARAGINE G: GLUTAMINE T: THREONINE T: TYROSINE C: CYSTEINE
which aa are acidic?
aspartic acid and glutamic acid
which aa are basic?
HAL :
H: histidine
A: arginine
L: lysine
what is the primary sequence?
number and sequence of aa in a polypeptide
once the primary sequence is formed, the single chain can twist into ?
a helix or lie along side itself to form a B pleated sheet. with the b pleated sheet - the two strands can lie in the same direction or in opp direction (antiparallel).
what are both a helices and B pleated sheets reinforced by?
hydrogen bonds- between the carbonyl oxygen and the hydrogen on the amino group.
what kind of structures are the A helix and the b pleated sheet?
secondary structure- contribute to the conformation of the protein.
what is the tertiary structure?
the 3D shape formed when the peptide chain curls and folds.
what are the 5 forces that create tertiary structure?
1) covalent disulphide bonds between two cysteine aa
2) electrostatic interactions between acidic and basic side chains
3) hydrogen bonds
4) van der Waals forces
5) hydrophobic side chains pushed away from water toward the centre of protein
what does proline do?
it induces a turn into the polypeptide and will disrupt the a helix and the b pleated sheet formation.
what is the quaternary structure?
when 2 or more polypeptide chains bind together , they from the polypeptide chain.
the denatured protein looses…
most of its secondary, tertiary and quarterly structure !
often, when the denaturing agent is removed , the protein will spontaneously refold into original conformation. this suggests that aa sequence plays a key role in the conformation of the protein.
what are cytochromes?
are proteins that need a prosthetic heme group in order to function. cytochromes get their name from the color that they add to the cell. ex ) hemoglobin and cytochromes of the ETC.
what are carbohydrates made of?
sugar and water
the empirical formula is C(H2O)
GLUCOSE
The ring form is favoured over the chain form.
the ring form has two anomers ( alpha glucose) and B GLUCOSE
what is the diff between the two anomers of glucose?
the hydroxyl group on the anomeric C and the methods group are on opp sides of the carbon ring ( on the alpha glucose)
on the beta glucose ( the hydroxyl group and methods group ) are on the same side of the carbon ring.
glycogen
branched glucose polymer with alpha linkages.
large amounts are in the muscle and liver cells.
which cells are capable of absorbing glucose against a concentration gradient?
certain epithelial cell in the digestive tract and proximal tubule of the kidney. this is done via secondary active transport, down the concentration gradient of sodium.
all other cells absorb glucose via facilitated diffusion.
insulin would inc the rate of facilitated diffusion for glucose. in the absence of insulin, only neural and liver cells are capable of absorbing sufficient amounts of glucose via facilitated transport.
plants form starch and cellulose from glucose.
starch has two forms. amylose and amylopectin.
cellulose has what linkages?
beta linkages - which most animals cannot digest. most animals have enzymes to digest the alpha linkages of starch and glycogen.
what are the 3 components of nucleotides?
a 5 carbon sugar
a nitrogenous base
a phosphate group
what are nucleotides joined together by?
phosphodiester bonds ! between the phosphate group of one nucleotide and the 3rd carbon of the pentose of the other nucleotide
Minerals
dissolved organic and inorganic ions inside and outside of the cell. they create electrochemical gradient across membranes, they assist in the transport of substances across the membrane. they can also combine and solidify to give strength to a matrix like hydroxyapatite in bone.
minerals also act as cofactors - assist enzymes or protein function.
