ch 6

Question 1

lipids are what and do what (three things)

Answer 1

oily/fatty substances that 1) in adipose cells, fat (triglycerides) store energy 2) in membranes, phospholipids make barriers 3) cholesterol is a special lipid that servers a precursor to steroid hormones

Question 2

lipids are what in regards to water, whats another word for the two terms

Answer 2

lipids are hydrophobic due to their c-c and c-h bonds that are nonpolar, hydrophobic are lipophilic and hydrophilic are lipophobic

Question 3

what are fatty acids made of?

Answer 3

long unsubstituted alkanes with a carboxylic acid at the end, and it is usually even numbered

Question 4

what is a unsaturated or saturated fatty acid? whats their respective fluidity?

Answer 4

unsaturated FA: FA’s with a double bond that causes them to have a kink to them which makes them more fluid.
saturated FA: FA’s without any double bonds but saturated with hydrogens which allows them to be densely packed together which makes them less fluid.

Question 5

what is the bond of the double bonded FA?

Answer 5

the bond is usually z or cis

Question 6

FA in a water solution creates what? why?

Answer 6

it creates a micelle which is a circular structure with hydrophilic heads and hydrophobic tails. this is driven by the hydrophobic effect, increased entropy in the water and decreased entropy in the grease

Question 7

what is the storage form of fatty acids? what is it made up of

Answer 7

triglycerides or triacylglycerol , it is made up of 3 fatty acids esterified to a glycerol backbone

Question 8

how is soap made, whats the name of this process, what makes soap special

Answer 8

soap is made by base-hydrolysis of triglycerides from fat to FA salts. this process is called saponification. soap is amphipathic

Question 9

what does amphiphatic mean?

Answer 9

has both hydrophilic and hydrophobic parts

Question 10

what is the more efficient storage of energy, glucose or fatty acids? why?

Answer 10

fatty acids because 1) the can be densely packed together more closely 2) stored fats are reduced by glucose is partly oxidized.

Question 11

why is reduced molecules better for energy

Answer 11

energy metabolism begins with oxidation to release energy

Question 12

membrane lipids are ? what are they derived from

Answer 12

they are phospholipids and they are derived from diacylglycerol or DG-P

Question 13

phospholipids are usually attached to what? give three examples

Answer 13

they are attached to a bigger more polar molecule and they can be choline, ethanolamine, and inositol

Question 14

phospholipids have what structure

Answer 14

hydrophobic head and hydrophilic tail

Question 15

what are the three determinants of fluidity in lipids?

Answer 15

degree of saturation, tail lengths, and amount of cholesterol

Question 16

how do hydrophilic molecules pass through cell membranes

Answer 16

membranes have proteins, channels, shunts that allow charged molecules to pass through

Question 17

what hormones can pass straight through the cell membrane? which ones cannot. where are each receptor

Answer 17

steroid hormones can pass through the membrane because hydrophobic and receptors are in cell. the peptide hormones cannot pass through membrane needing to use channels and proteins, receptors are on the cell membrane

Question 18

once a peptide hormone binds what occurs

Answer 18

the protein receptor transmits a signal into the cell and starts the second messenger cascade

Question 19

what are terpenes and whats their formula

Answer 19

they are built from isoprene units with (C5H8)n as formula

Question 20

how are isoprenes named? what are the names of the main ones?

Answer 20

they are named by how many isoprene units they have. monoterpene (2) , sesquiterpene (3), and diterpene (4)

Question 21

monoterpene

Answer 21

2 isoprene units

Question 22

sesquiterpene

Answer 22

3 isoprene units

Question 23

diterpene

Answer 23

4 isoprene units

Question 24

what is squalene

Answer 24

triterpene (6 units) that helps with making steroids and part of earwax

Question 25

terpenoids

Answer 25

natural or synthetic derived species built from isoprene skeleton and bonded together with other elements

Question 26

what is an example of a terpene that is also a vitamin

Answer 26

vitamin A

Question 27

what are steroid? once carried through blood, where do steroids go?

Answer 27

steroid is a cholesterol with a tetracyclic rings and a polycyclic amphipath. they are carried through blood with fats and proteins into the lipoproteins

Question 28

what are the two sex hormones made from steroids

Answer 28

testosterone and estradiol

Question 29

what is a sphingolipid and what makes it different to phospholipids

Answer 29

just like phospholipid but instead of glycerol backbone, it has a sphingosine backbone

Question 30

what is the most important sphingolipid and what does it do

Answer 30

sphingomyelin, it is a component of the myelin sheath that protects neurons

Question 31

what are waxes

Answer 31

long chain fats esterified to long chain alcohols, very hydrophobic

Question 32

what are fat soluble vitamins and what are some examples of them

Answer 32

they are vitamins absorbed with dietary fats, and stored in adipose tissue and liver. they are vitamin A, D,E, and K

Question 33

vitamin A is for

Answer 33

terpenoid, essential for vision, growth, and immune function

Question 34

vitamin D is for

Answer 34

derived from cholesterol (steroid) its essential for blood regulation of calcium and phosphate

Question 35

vitamin E is for

Answer 35

a group of compounds called tocopherols, they are essential antioxidants

Question 36

vitamin K is for

Answer 36

an important coenzyme in activation of blood clotting proteins

Question 37

what are prostaglandins

Answer 37

a group of molecules derived from 20 carbon fatty acids that do different things depending on receptor like smooth muscle contraction, blood vessel diameter, gastric integrity

Question 38

when starting fat digestion, what occurs to fat

Answer 38

chylomicrons of fat and lipoproteins are transported via lymphatic system and blood to diff organs and this fat is hydrolyzed to free the fatty acids to go through beta oxidation

Question 39

where does beta oxidation occur?

Answer 39

mitochondrial matrix

Question 40

beta oxidation uses how many ATP's to do what (with name of enzyme)

Answer 40

it uses 2 atp's to make fatty acid acetyl coA madeby acetyl coA synthase

Question 41

what occurs in beta oxidation

Answer 41

a fatty acid enters and acetyl-coA's are cleaved (every 2 carbons) but the last round you cleave 4 carbons which is then made into two acetyle coA's IMPORANT NOTE: a round is counted after every 2 c until the last round that cleaves four. 12 carbon FA has 5 rounds of b-oxidation

Question 42

how many nadh and fadh2 is made during each round of beta oxidation

Answer 42

you make 1 nadh and 1 fadh2

Question 43

can a unsaturated fa go through beta oxidation? if so, how? if not why?

Answer 43

yes, it can, it goes along the same process until it hits the double bond and then uses isomerase and a reductase enzyme to remove double bond

Question 44

why does ketogenesis occur and where does it occur

Answer 44

it occurs when all glycogen stores are depleted (starvation) and no sugar is getting to the brain and it occurs in the mitochondrial matrix in the liver

Question 45

what does ketogenesis make? where is this product derived from?

Answer 45

ketogenesis made ketone bodies and this product is derived from acetyl-coa

Question 46

if theres glucose in the blood but it doesnt enter the cell, what occurs? what disease is this?

Answer 46

ketogenesis begins and this is diabetes type 1

Question 47

what occurs when there is too many ketone bodies

Answer 47

ketoacidosis causes too much acidity in the body

Question 48

what occurs to ketones after they pass the blood brain barrier

Answer 48

they can be converted back into acetyl-coA

Question 49

where does FA catabolism occur? anabolism?

Answer 49

FA catabolism occurs in the mitochondrial matric and anabolism occurs in the cytoplasm

Question 50

what is the first step of FA synthesis

Answer 50

1. the repeated addition of 2 carbon units creating acetyl coA and this acetyl coA is carboxylated by acetyl coA carboxylase to make malonyl coA (3c)

Question 51

second step of FA synthesis

Answer 51

2. an acetyl coa binds to a part of FA synthase called ACYL CARRIER PROTEIN or ACP. it is then shifted to another part of the enzyme to allow malonyl coA to bind ACP

Question 52

third step of FA synthesis

Answer 52

the acetyl coa binds with that malonyl to make a 5c molecule which is then decarboxylated to make a 4c molecule that then gets reduced by NADPH.

Question 53

fourth step of FA synthesis

Answer 53

the process continues with the addition of the four carbon molecule (decarboxylated 5c molecule that came from malonyl and acetyle coa) until you make a 16 carbon FA

Question 54

what can the amine part of the amino acid be used for

Answer 54

to make urea to discard or make a nitrogenous compound

Question 55

what can the carbon skeleton part of the amino acid be used for

Answer 55

it can make glucose (glucogenic AA) or acetyl coa (ketogenic AA)

Question 56

FA synthesis occurs in what organ

Answer 56

liver

Question 57

in a well fed state, what processes are favored

Answer 57

glycolysis, glycogenesis, FA synthesis

Question 58

in a starving state, what processes are favored

Answer 58

glycogenolysis, beta oxidation, gluconeogenesis

Question 59

what are the main macromolecules? what are their monomers?

Answer 59

macromolecules: proteins, lipids, carbohydrates, and nucleic acids. their monomers are: amino acids, fatty acids, monosacc, and nucleotides

Question 60

Cholesterol in a cell membrane does what to the fluidity at low temperature? What occurs to freezing point?

Answer 60

At low temp, cholesterol allows an increase in fluidity. It causes freezing point to decreased

Question 61

Cholesterol in the cell membrane at high temperatures causes what to fluidity? The bag occur to melting point?

Answer 61

At high temps cholesterol decreases fluidity and therefore increasing melting point