Biochemistry Exam 3 Flashcards
What are:
- Soluble in organic solvents (ether, chloroform)
- Serve multiple purposes in the body like storing energy, protecting, insulating internal organs, and act as chemical messengers
- Important feature in cell membranes, fat-soluble vitamins, and steroid hormones
- Lipids
What are esters that can be hydrolyzed to give fatty acids and other molecules?
Lipids such as:
- waxes,
- triacylglycerols,
- glycerophospholipids
- sphingolipids
_______ and ______ contain the alcohol glycerol.
-Triacylglycerols and glycerophospholipids
What contains the amino alcohol sphingosine?
- Sphingolipids
What can not be hydrolyzed and doesn’t contain fatty acids?
- Steriods
What contain a fused four-membered ring system?
- Steriods
What contain long carbon chains and carboxyli groups?
- Fatty acids
______ long, unbranched carbon chains with a carboxylic acid group at the end. Typically 12–18 carbon atoms long and insoluble in water because of the long carbon chain.
- Fatty acids
Fatty acids are _______ when they do not contain C = C double bonds in the carbon chain.
- Saturated ( Has properties similar to an alkane)
Fatty acids are ______ when they contain C = C double bonds in the carbon chain.
- Unsaturated
Fatty acids can be ______, with only one double C = C bond in the carbon chain.
- Monounsaturated ( Has properties similar to an alkene)
Is the carboxylic acid part of the fatty acid hydrophobic or hydrophilic?
- Hydrophilic
What makes fatty acids insoluble in water?
- Long Hydrophobic carbon chain
Fatty acids can be ______, with at least two double C = C bonds in the carbon chain
- Polyunsaturated
What requires a significant amount of energy and high temperatures to separate and melt?
- Saturated Fatty acids, because the contain only single carbon bonds that fit closely together in a regular pattern, with strong dispersion forces between carbon. cahins.
True or False almost all naturally occurring unsaturated fatty acids have one or more cis double bonds?
-True
If interactions between molecules are reduced by irregular molecule shape due to cis bonds, what will happen?
- The reduced interactions in fatty acids with cis bonds reduce the melting point of the molecules.
_______ cannot synthesize sufficient amounts of polyunsaturated fatty acids such as linoleic acid, linolenic acid, and arachidonic acid.
- Humans
What Fatty acids are normally solids at room temperature?
- Saturated Fatty Acids
Fatty acids such as linoleic acid, linolenic acid, and arachidonic acid are knowen as _____.
- Essential Fatty Acids, because they must be obtained from the diet.
______ are also known as eicosanoids, formed from arachidonic acid, a polyunsaturated fatty acid with 20 carbon atoms.
- Prostaglandins
______ have many functions, such as lowering or raising blood pressure and stimulating contraction and relaxation of the smooth muscle of the uterus.
- Prostaglandins
Prostaglandin E (PGE) has a _____ group on carbon 9
- ketone
Prostaglandin F (PGF) has a _____ group on carbon 9
- hydroxyl
When tissues are injured, _______ is converted to prostaglandins that produce inflammation and pain in the area.
- arachidonic acid
_____ are hormone-like substances produced in small amounts in most cells.
- Prostaglandins
What essential fatty acid (EFA) is the precursor of arachidonic acid, the polyunsaturated fatty acid with 20 carbon atoms?
- Linoleic
True or False prostaglandins are broken down quickly?
- True
_____ block production of prostaglandins, decreasing pain and inflammation.
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
____ such as those in vegetable oils and fish are recognized as more beneficial to health than saturated fats.
- Unsaturated fats
______ is an ester of a long-chain fatty acid and a long chain alcohol, each containing from 14 to 30 carbon atoms.
- A wax
How are fatty acids stored in the body?
- As triacylglycerols (triglycerides)
How are triacylglycerols formed and how are they named?
- esters of glycerol, a trihydroxy alcohol, and fatty acids.
- formed when three hydroxyl groups of glycerol react with the carboxyl groups of three fatty acids.
- named by changing glycerol to glyceryl and naming the fatty acids as carboxylates.
True or False: Triacylglycerol may contain different fatty acids, such as the triacylglycerol made from stearic, oleic, and palmitic acids.
- True
______ have low melting points because they have a higher percentage of unsaturated fatty acids than do animal fats.
- Vegetable oils
This happens double bonds in unsaturated fatty acids react with hydrogen gas to produce carbon–carbon single bonds.
- Hydrogenation reaction, hydrogen gas is bubbled through the heated oil typically in the presence of a nickel catalyst.
What process causes:
- the addition of hydrogen is stopped before all the double bonds in a liquid vegetable oil become completely saturated.
- the partial hydrogenation of a liquid vegetable oil changes it to a soft, semisolid fat.
- the more saturated product has a higher melting point.
- Commerical hydrogenation
How are triacylglycerols hydrolyzed (split by water)?
- In the presence of strong acids such as HCl or H2SO4, or digestive enzymes called lipases.
_____ is the reaction of a fat with a strong base such as NaOH in the presence of heat.
- Saponification (forming soaps “salts of fatty acids”)
_____ are a family of lipids similar in structure to triacylglycerols; they include glycerophospholipids
and sphingomyelin.
- Phospholipids
What contains two fatty acids that form ester bonds with the first and second hydroxyl groups of glycerol and
a hydroxyl group that forms an ester with phosphoric acid, which forms another phosphoester bond with an amino alcohol?
- Glycerophospholipids
What contains sphingosine instead of glycerol and a fatty acid, phosphate, and an amino alcohol.
- Sphingomyelin
What amino alcohols are found in glycerophospholipids?
- choline, serine, and ethanolamine and they are ionized at physiological pH of 7.4.
What are two types of glycerophospholipids that are
abundant in brain and nerve tissues and found in egg yolk, wheat germ, and yeast?
- Lecithin and Cephalin
What contains both polar and nonpolar regions that allow them to interact with polar and nonpolar substances. They have a polar head containing the ionized amino alcohol and phosphate portion, which is strongly attracted to water. They also have a nonpolar hydrocarbon tail portion soluble only in nonpolar substances such as lipids.
- Glycerphospholipids
What are abundant in the white matter of the myelin sheath?
- Sphingomyelin
What is found in sphingolipids and sphingomyelin?
- Sphingosine
True or false sphingosine is along chain of amino alcohol?
- True
- sphingosine, a long-chain amino alcohol that replaces glycerol.
- an amide bond formed by the amine group on sphingosine to a fatty acid.
- a hydroxyl group that forms an ester bond with phosphate, which forms another phosphoester bond to choline or ethanolamine.
- Sphingomyelin
In multiple sclerosis what is lost from the myelin sheath, which protects the neurons in the brain and spinal cord?
- Sphingomyelins
_____, the 16-carbon saturated fatty acid, is the most common fatty acid found along with the ionized amino alcohol choline in the sphingomyelin of eggs.
- Palmitic acid
All steroids contain a _____, which consists of
three cyclohexane rings and one cylopentane ring, fused together.
- rings designated as A, B, C, and D.
- numbered carbon atoms beginning in ring A.
- two methyl groups at positions 18 and 19.
- steroid nucleus
Where is cholesterol obtained from?
- meats, milk, and eggs
Where is cholesterol synthesized at?
- liver
_______ is needed for cell membranes, brain and nerve tissue, steroid hormones, and vitamin D.
- Cholesterol
What helps with the absorption of cholesterol?
- Bile salts
Where are bile salts synthesized and stored?
- Synthesized in the liver and stored in the gallbladder
What happens when large amounts of cholesterol accumulate in the gallbladder?
- Gallstones are formed
Lipids are nonpolar and are made more soluble by combining them with glycerophospholipids and proteins to form water-soluble complexes called _______.
- Lipoproteins
______ differ in density, composition, and function.
- Lipoproteins (HDL / LDL)
_____ are chemical messengers that serve as a communication system for the body and are produced from cholesterol.
- Steroid hormones
What do mineralocorticoids help balance?
What do glucocorticoids help regulate?
- Electrolyte balance
- Regulation of glucose level
Where are adrenal corticosteroids produced?
- are produced by the adrenal glands located on the top of each kidney.
What adrenal corticosteroid helps regulate electrolytes and water balance by the kidneys?
- aldosterone
What adrenal corticosteroid helps
- glucocorticoid, which increases blood glucose level and stimulates the synthesis of glycogen in the liver.
Why is cholesterol a sterol?
- because is contains an oxygen atom as a hydroxyl group on carbon 3.
How are lipids made more soluble, allowing them to be transported through the bloodstream to the tissues?
- They are combined with phospholipids and proteins forming lipoproteins.
True or False: Most lipids are nonpolar and insoluble in the aqueous environment of blood?
- True
How are Cholesteryl ester formed?
- Esterification of the hydroxyl group in cholesterol with a fatty acid.
Where does LDL (bad) carry cholesterol?
- Deposits cholesterol in the arteries (plaque)
Where does HDL (good) carry cholesterol?
- Liver where it is converted to bile salts
What are derivatives of ammonia, NH3, in which one or more hydrogen atoms are replaced with alkyl or aromatic groups and contain N attached to one or more alkyl or aromatic groups?
- Amines
In the IUPAC names for amines, the e in the corresponding alkane name is replaced with ____.
- amine
_____ with a chain of three or more carbon atoms are numbered to show the position of the —NH2 group and any other substituents.
- Amines
If there is an alkyl group attached to the nitrogen atom, the prefix N and the alkyl name are placed in front of the amine name.
If there are two alkyl groups bonded to the N atom, the prefix N is used for each, and they are listed alphabetically.
- Naming Amines
Common names are often used when alkyl groups are not branched.
- List the names of the alkyl groups bonded to the N atom in alphabetical order in front of amine.
- Use prefixes di and tri to identify duplicate alkyl substituents.
- Common names for Amines
The amine of benzene is named ____ by IUPAC.
- Aniline
A _____ amine has one carbon group bonded to the nitrogen atom.
- primary (1°)
A _____ amine has two carbon groups bonded to the nitrogen atom
- secondary (2°)
A _____ amine has three carbon groups bonded to the nitrogen atom.
- tertiary (3°)
____ contain polar N—H bonds, which allow primary and secondary amines to form hydrogen bonds with each other, while all amines can form hydrogen bonds with water.
- Amines
_______ can only form hydrogen bonds with water molecules.
- Tertiary amines
______ is not as electronegative as oxygen, so hydrogen bonds in amines are weaker than the hydrogen bonds in alcohols.
- Nitrogen
_____ have boiling points that are higher than those of alkanes but lower than those of alcohols.
- Amines
_____ amines can form more hydrogen bonds and have higher boiling points than secondary (2°) amines of the same mass.
- Primary (1°)
amines cannot form hydrogen bonds with each other and have lower boiling points than primary or secondary amines of the same mass.
- Tertiary (3°)
Amines with _____ carbon atoms, including tertiary amines, are soluble in water.
- one to six
As the number of _____ in an amine increases in the nonpolar alkyl portions, the effect of hydrogen bonding is diminished.
- carbon atoms
In a neutralization reaction,
- an amine acts as a base and reacts with an ____ to form an ammonium salt.
- the lone pair of electrons on the_____ accepts H+ from an acid to give an ammonium salt; no water is formed.
- acid
- nitrogen atom
An ______ is named by using its alkylammonium ion name followed by the name of the negative ion.
- ammonium salt
In a quaternary ammonium salt,
- a nitrogen atom is bonded to _____, which classifies it as a quaternary (4°) amine.
- the nitrogen atom has a ______ and is not bonded to an H atom.
- four carbon groups
- positive charge
What are ionic compounds with strong attractions between the positively charged ammonium ion and an anion, usually chloride?
- solids at room temperature, odorless, and soluble in water and body fluids.
- Ammonium Salts
A ______ is a cyclic organic compound that consists of a ring of five or six atoms, of which one or two are nitrogen atoms. `
- heterocyclic amine
_____ is a five-atom ring with one nitrogen atom and two double bonds
- Pyrrole
____ which is a ring of four carbon atoms and one nitrogen atom, all with single bonds.
- pyrrolidine
____ is a five-atom ring that contains two nitrogen atoms.
- imidazole
_____ responsible for the pungent aroma and taste of black pepper, is a six-atom heterocyclic ring with a nitrogen atom.
- piperidine
_______ are physiologically active compounds produced by plants that contain heterocyclic amines and are used in anesthetics, in antidepressants, and as stimulants, and many are habit forming.
- Alkaloids
Morphine and codeine are?
- alkaloids obtained from the oriental poppy plant.
- used as painkillers and in cough syrups.
Within a nerve cell, _____ are synthesized and stored in vesicles at the end of the axon terminal.
- neurotransmitters
A _____ is a chemical compound that transmits an impulse from a nerve cell to a target cell. Target cells may be another nerve cell, a muscle cell, or a gland cell.
- neurotransmitter
Neurotransmitters can be removed from the receptors in different ways:
- The neurotransmitter diffuses away from the synapse.
- Enzymes in the receptors break down the neurotransmitter.
- Reuptake returns the neurotransmitter to the vesicles, where it is stored.
_____ contain nitrogen atoms as amines and alkylammonium ions
- they are synthesized from compounds such as amino acids obtained from our diets.
- their amino groups are usually ionized, forming ammonium cations and carboxylate anions.
- Neurotransmitters
