BioChem Block 3 Flashcards
What does the name Lipid encompass?
Fatty Acids and Steroids Waxes Triacylglycerols Glycerophospholipids Sphingomyelins
What are the parts of a wax?
Long chain alcohol
Fatty acid
What are the parts of a triacylglycerol?
Glycerol
Fatty acid x 3
What are the parts of a glycerolphospholipid?
Glycerol
Fatty acid x 2
Phosphate
Amino Alcohol
What are the parts of a sphingomyelin?
Sphingosine
Fatty Acid
Phosphate
Amino alcohol
What are lipids soluble in?
Organic solvents- ether, chloroform
Not water
Define fatty acid
Long, unbranched C chain w/ carboxylic acid group
What is the solubility of fatty acids?
Insoluble due to long hydrophobic C chain
Naturally occurring fatty acids are - C in length?
12-20
Define saturated fatty acid
only C-C- single bonds
Long chain fatty acids have similar properties to what?
Alkanes
Define unsaturated fatty acid
one or more C=C double bonds
Define monounsaturated fatty acid
Long C chain with one double bond
Monounsaturated fatty acids have properties similar to what?
Alkenes
Define polyunsaturated fatty acid
Contains at least two C=C double bonds
_____ fatty acids can be drawn in -cis or -trans form
Which form is more naturally occurring?
Unsaturated
-cis
Fatty acids are usually __ at room temps
Solid
What has a lower melting point, saturated or unsaturated fatty acids?
Unsaturated
Saturated is higher due to ability to pack together
Unsaturated fats are ___ at room temps?
Liquid
What are two polyunsaturated fats the human body can not synthesize?
Linoleic acid
Linolenic acid
The human body can synthesize some fatty acids from ____ and ____
Carbs
Other Fatty acids
Why is linoleic acid important in the human body?
Why is this important?
Precursor to arachidonic acid
Vital in forming prostaglandins during tissue injury
Prostaglandins are AKA ?
Eicosanoids
What is Prostaglandin E soluble in?
What is Prostaglandin F soluble in?
E- ether
F- phosphate buffer, fosfat
How do Prostaglandin E and F differ in structure?
E= ketone group on C #9 F= hydroxyl group
Define wax
Ester of long chain fatty acid and long chain alcohol each with 14-30 C
What form are fatty acids stored in within the body?
Triacyglycerols aka triglycerides
Define triacylglycerol
Triesters of glycerol and fatty acids
3 hydroxyl groups of glycerol form ester bonds w/ carboxyl groups of 3 fatty acids
What type of alcohol is glycerol?
Trihydroxyl
Most naturally occurring triacylglycerols contain glycerol bonded to ?
2-3 different fatty acids
Define fat
Triacylglycerol that is solid at room temp and comes from animal sources
Define oil
Triacylglycerol that is a liquid at room temp and obtained from plants
What has a higher melting point, animal fat or vegetable oil?
Animal is higher
Animal fat contains more saturated fatty acids
What does the chemical reactions of triacylglycerols involve?
Hydrogenation of double bonds in fatty acids
Hydrolysis and saponification of ester bonds between glycerol and fatty acids
Define hydrogenation in triacyglycerols
H gas bubbled through heated oil typically w/ nickel catalyst
Causes H atoms to add to one or more C=C double bond to form C-C single bonds
What does complete hydrogenation of triacylglycerols produce?
Partial hydrogenation?
Brittle product
Soft, semisolid fat
What is the benefit of partial hydrogenation of triacyglycerols?
Contain more saturated fatty acids
No cholesterol
What occurs in the hydrolysis of triacylglycerols?
Split by stron acid or lipase
Product of the hydrolysis of the ester bonds = glycerol and 3 fatty acids
What is the solubility of a hydrolysis tricylglycerol?
Glycerol- polar, soluble
Fatty acids- nonsoluble
What is saponification?
Fat is heated w/ strong base to form glyceral and salts of fatty acids
What is the process name that soaps are made from?
Saponification
What type of soap is the result of NaOH?
What is the product of KOH?
NaOH= solid, moldable soap KOH= soft, liquid soap
An oil that is polyunsaturated produces _____ soap
softer
Phospholipids are similar to ____ and contain _____ and _____
Similar to triacylglycerol
Contain glycerophospholipids and spingomyelins
What are the components of a triacylglycerol?
1 glycerol
3 fatty acids
What are the components of a glycerophospholipid?
1 glycerol
2 fatty acid
1 phosphate
1 amino alcohol
What are the components of spingomyelin?
1 spingosine
1 fatty acid
1 phosphate
1 amino alcohol
What are the 3 alcohols found in glycerophospholipids?
Choline
Serine
Ethanolamine
What happens to Choline, Serine and Ehtanoamine in the body at a pH of 7.4?
Ionize
What group do lecithins and cephalins belong to?
Where are they found and obtained from?
Glycerophospholipids
Brain and nervous tissue
Yolk, wheat germ, yeast
What does lecithins contain?
What does cephalins contain?
Choline
Ethanolamine, sometimes serine
What makes up the head in a glycerophospholipid?
What makes up the tail?
Head= Ionized amino alcohol and phosphate Tail= hydrocarbon chains
What is the make up of a sphingomyelin?
Amine group of sphingosine foms amide bond w/ fatty acid
Hydroxyl group forms ester bond w/ phosphate, forms additional phosphoester bond to choline or ethanolamine
Which phospholipid is targeted by Multiple Sclerosis?
Sphingomyelin
Which vitamin has shown to reduce or slow the effects of MS on the nervous system?
Vit D
The nonpolar hydrocarbon tails of glycerophospholipids are only soluble in what?
Nonsoluble substances like lipids
What is the most common fatty acid found along with ionized amino alcohol in sphingomyelin?
Palmitic acid, 16c saturated fatty acid
What makes up the steroid nucleus?
3 cyclohexane rings
1 cyclopentane ring
How does the steroid nucleus end?
With 2 methyl groups
Why is cholesterol a -sterol?
Contains O atom as hydroxyl group on C #3
Where are the double bonds in cholesterol?
Where are the methyl groups?
Where is the C chain?
C#5 and 6
C #10 and 13
C #17
Cholesterol levels are considered elevated if total plasma cholesterol is above _____
200mg/dL
What is the effect of bile salt on cholesterol uptake?
Bile salts act like soap and break down large drops to small drops, increases surface area for lipase to digest fats
How are lipids made more soluble for transport through the body?
Combining them with phospholipids and proteins to form lipoproteins
What are the prevalent form of cholesterol in the blood?
Cholesteryl
How are cholesteryls formed?
Esterification of hydroxyl group in cholesterol w/ fatty acid
What are the very low density lipoproteins called?
Chylomicrons
The density of lipoproteins increases as the percentage of ____ increases
Proteins
What is the function of LDL?
Carries cholesterol to tissues for use in synthesis of cell membranes and steroid hormones.
What is the function of HDL?
Picks up cholesterol from tissue and carries it to the liver to be converted to bile salts
What is the function of chylomicrons?
Carry triacylglycerols from intestines to liver, muscle and adipose tissue
What type of patient usually has elevated serum triglyceride levels?
Alcoholics
What is the most important and abundant steroid in the body?
Cholesterol
Function of aldosterone?
Regulates electrolytes and water balance by kidneys
Function of cortisone
Glucocorticoid
Increases blood glucose levels
Stimulates glycogen synthesis by liver
Define amine and amide
Organic compounds containing N
Amino acids, proteins and nucleic acids all belong in what category?
Amines
Amines exert strong physiological effects and include what examples?
Decongestants
Anesthetics
Sedatives
Dopaine
Histamine
Epi
Amphetamine
What are examples of naturally occurring amines that are obtained from plants?
Alkaloids
Caffeine
Nicotine
Cocaine
Digitalis
Define Amine
Ammonia derivative
N has 3 bonds to H atoms
N is bonded to 1/2/or3 alkyl or aromatic groups
How are Amines names?
IUPAC: alkane e replaced w/ amine. 3 or more C numbered to show position of -NH2 group
Common: alkyl/aromatic named alphabetically w/ amine at end
Prefixes di- or tri- are used for two or three identical substituents
If alkyl group is attached to N atom, prefix N- is added followed by alkyl name.
Two alkyl groups bonded to N, N prefix used for each in alphabetical order
How are Aromatic Amines named?
Aniline
What is the simplest aromatic amine?
Aniline
What is aniline used for?
Dyes for wool/cotton/jeans
Acetaminophen synthesis
How are amines classified?
Counting number of C bonded to N atom
1= N bonded to one alkyl group
2= N bonded to two alkyl groups
3*= N bonded to three alkyl groups
What are the polarity properties of Amines?
Polar N-H allows 1* and 2* to form H bonds w/each other
All amines can form H bonds w/ water
Which bonds are weaker, H bonds in amines or H bonds in alcohols?
Amines, N is not as electronegative as O
What kind of boiling points do amines have?
Higher than alkanes
Lower than alcohols
1- higher than 2 w/ the same mass
1- highest, 3 lowest
Why can’t 3* amines H bond with each other?
No N-H bonds
What are the solubility properties of amines?
1* can form more H bonds than 2*
Small amines- soluble
More than 6C= H bonding diminished due to hydrocarbon chains
Do Amines act as an acid or a base?
Base, due to lone e- pair on N
What are the products when amine reacts with water?
Pos charge alkylammonium ion
Neg charge hydroxide ion
New product named by adding ammonium ion to alkyl group
What happens when a amine reacts with an acid?
Forms ammonium salt
Lone e- on N accepts H from acid
No water is formed
New product named by alkylammonium ion name followed by name of the negative ion
Define quaternary ammonium salt
N atom bonded to 4 C groups
Choline is an example of what type of amine?
Quaternary ammonium ion
It’s N is not bonded to an H
Properties of ammonium salts at room temp?
Solid, odorless, soluble
Define free amine/free base
When ammonium salt reacts w/ strong base and converted back to amine
Define heterocyclic amine
Cyclic organic compound w/ one or two N atoms
What is the simplest five atom heterocyclic amine?
Pyrrolidine- 4C and 1N w/ all single bonds
Heterocyclic amines with two or three double bonds have aromatic properties similar to _____?
Benzene
Define Alkaloid
N containing component produced by plants
Define Neurotransmitter
Chemical component that transmits an impulse from a nerve cell to another nerve/muscle/gland cell.
What part of the cell are neurotransmitters made?
Made and stored in vesicles at axon terminals
Neurotransmitters are removed from receptors in what 3 ways?
Diffusion
Enzymatic break down
Reuptake
Neurotransmitters contain N atoms as ____ and ____ ions
Amine
Alkylammonium ions
Neurotransmitters are synthesized from amino groups that undergo what type of changes?
Amino groups ionized to form Ammonium cations
Carboxyl groups ionized to form carboxylate anions
What are some examples of important amine neurotransmitters>
Acetylcholine Dopamine Norepinephrine Epinephrine Serotonin Histamine Glutamate GABA
What effects does ACh have on the body?
Communicates with NS and muscle
Regulates muscle activation
Learning
Short term memory
How is ACh degraded in a synapse?
Enzymatically that hydrolyze ester bonds degrading ACh into choline and acetate
What is the most important catecholamine neurotransmitter?
Dopamine
Epi
Norepi
What functions does dopamine have on the body?
Energy Feeling of enjoyment Muscle movement control Regulation of sleep-wake cycle Improves cognition, attention, memory and learning
How is epinephrine synthesized?
Addition of methyl group to amine group
What is serotonin synthesized from?
Tryptophan
What is the most abundant neurotransmitter in the NS?
Glutamate
What does glutamate stimulate the synthesis of?
Nitrogen oxide
What causes a condition called excitotoxicity?
Reuptake of glutamate does not occur fast enough
Excess glutamate at receptor destroys bran cells
What is the most common inhibitory neurotransmitter in the brain?
GABA
Define amides
Derivative of carboxylic acids in which amino group replaces hydroxyl group
What is the functional group of amides?
Carbonyl group attached to an amine
Define peptide bond
Amide bond that links aa in proteins
What are some examples of medically important amides?
Acetaminophen
Phenobarbital
Penicillin
How are amides produced?
Amidation or condensation
Carboxylic acid reacts w/ ammonia, 1* or 2* amine
Water is eliminated, carboxylic acid and amine join to form amide (similar to formation of an ester)
Why are 3* amines unable to undergo amidation?
Don’t contain H atom
How are amides named?
IUPAC and Common- o/ic acid from carboxylic acid replaced w/ amide
If alkyl groups are present, N is used as prefix before the amide
What is the only amide that is liquid at a room temperature?
Methanamide
All others are solids
What are the melting properties of amides?
1* can form more H bonds, have the highest melting point
2* for fewer H bonds, have lower point than 1*
3* can not form H bonds, have lowest melting point
What are the solubility properties of amides?
1-5C= soluble
The specific order of amino acids in a chain determines _________ which will determine ______
How the protein will fold into a 3D shape
3D shape determines the protein’s function
How many amino acids are commonly found in the proteins of living organisms?
20
What is the components of an amino acid?
Central C atom (alpha carbon)
2 functional groups: ammonium (-NH3) and carboxylate (-COO)
What are the R groups of the nonpolar amino acids?
H
Alykyl
Aromatic
What are the the three types of polar amino acids?
Polar neutral: hydroxyl, thiol, aminde
Polar acidic: carboxylate
Polar basic: ammonium ion
What are the Nonpolar Amino Acids?
Glycine Alanine Valine Leucine Isoleucine Phenylalanine Methionine Proline Tryptophan
What are the Polar Neutral Amino Acids?
Serine Threonine Tyrosine Cysteine Asparagine Glutamine
What are the Polar Acidic Amino Acids?
Aspartate
Gluamate
What are the Polar Basic Amino Acids?
Histidine
Lysine
Arginine
Define peptide bond?
Amide bond that forms when COO group of one aa reacts with NH3 group on another aa
What is also produced when a peptide bond is made?
Water
O from carboxylate and 2 H atoms from ammonium end
What are the bonds called when 2-5 peptide bonds are made?
What are they called when there are more than 6 peptide bonds?
Dipeptide
Tripeptide
Tetrapeptide
Pentapeptide
6+= polypeptide
Proteins are polypeptides with ___aa that have a biological activity
50aa or more
Define the Primary Structure of proteins?
AA sequence held together by peptide bonds to form N and C terminus
Define N-terminus
Amino acid with a free, unbonded, NH3 group
Define C terminus
Amino acid with free unbonded COO group
Peptides are drawn and named in what direction?
From N-to-C-terminus
How do you name peptides?
Everything except amino acid at C-terminus ends with -yl
The biological function of peptides and proteins depends on what?
Specific sequence of AA
What was the first protein to have it’s primary structure determined?
How many AAs does it have?
Insulin
Chain A= 21aa
Chain B= 30
How are the AAs in insulin held together?
Disulfide bonds by thiol groups of cysteine amino acids
Define Secondary Structure?
Describes the type of structure that forms when protein/peptide bond within/between polypeptide chain
What are the two most common types of Secondary Structures?
Alpha helix
Beta pleated sheets
Define Alpha Helix?
H bonds between C=O groups and H atoms of the n-H groups of the amide bonds in the next turn
Which way do all R groups of an Alpha Helix point?
Outward
Define Beta Pleated Sheet?
H bonds between O atoms in carbonyl group and H atoms in N-H groups of nearby by polypeptide chain
When/where can a Beta Pleated Sheet form?
Between adjacent polypeptide chains
Within same polypeptide chain
What give Beta Pleated Sheets it’s strength and durability?
H bonds
The tendency to form various kinds of secondary structures depends on what?
AA in particular segment of the polypeptide chain
Typically, Beta Pleated Sheets contain mostly what type of AAs?
Ones w/ small R groups
Glycine, Valine, Alanine, Serine- extend above and below the sheet
Alpha Helices usually contain mostly what type of AAs?
AAs with large R groups
Histidine
Leucine
Methionine
What is the most abundant protein in the body?
Collagen
What gives Collagen it’s strong structure?
3 polypeptides twisted into a triple helix
-OH groups of hydroxyproline and hydroxylysine that H bond between the peptide chains
Glycine is predominantly made up of what AAs?
Glycine
Proline
Alanine
Diet that is efficient in Vitamin C will be evident by which secondary structures becoming weak?
Triple helices
Define Tertiary Structure
Attractions/repulsions between R groups of AAs
What type of interactions help stabilize/hold the Tertiary Structure?
Hydrophobic Interactions Hydrophilic Salt Bridges H bonds Disulfide bonds
Define Quaternary Structure
Active protein that consists of two or more polypeptide chains
How are peptide bonds hydrolyzed in the stomach?
Primary structures are broken by breaking the covalent peptide bonds
What structures does denaturation effect?
Secondary
Tertiary
Quaternary
Primary left unaffected
