Exam 5 Flashcards
Contain an aldehyde or ketone and multiple alcohols
Carbohydrates
What is another name for saccharides?
Carbohydrates
What are the functions of carbohydrates?
Energy production
Carbon supply for making cell parts
Energy storage
Structure of certain cells and tissues
What are the 3 classes of carbohydrates?
Monosaccharides
Disaccharides
Polysaccharides
What is an achiral carbon?
Superimposable on mirror image
What is a chiral carbon?
Non-superimposable on mirror image
What is a chiral MOLECULE?
Has at least one carbon atom bonded to 4 different groups
What is a D notation?
the -OH is on the right of the bottom most CHIRAL carbon
What is an L notation?
the -OH is on the left of the bottom most CHIRAL carbon
3 carbon atoms
triose
4 carbon atoms
tetrose
5 carbon atoms
pentose
6 carbon atoms
hexose
What does a ketone look like?
Has a C double bond O on the interior
What does an aldehyde look like?
Has an O double bonded to a C on the outside
What are the important monosaccharides?
Glucose Fructose Galactose Ribose Deoxyribose
Most important simple sugar
AKA Dextrose
Doesn’t need to be broken down
Makes up starch, cellulose, glycogen, sucrose, lactose and maltose
Glucose
Sweetest carbohydrate AKA Levulose or fruit sugar Found in fruit juices and honey Converts to glucose in the body Used widely in the food and beverage industry
Fructose
Part of lactose
Used in cell membranes of brain and nervous system
Galactose
Only slightly sweet
Component of ATP
Component of RNA
Ribose
Used in synthesis of DNA
Deoxyribose
Properties of monosaccharides
Taste sweet White crystalline solids High melting points Extremely soluble in water Easily oxidized and reduced Exist primarily in cyclic structures
Two monosaccharides linked together by hydrolysis
Disaccharides
Glucose + fructose
Table sugar
Obtained from sugar cane and sugar beets
Sucrose
Glucose + galactose
Milk sugar
Found in milk and milk products
Lactose
Glucose + glucose
Malt sugar - used in cereals, candies, and brewing
Obtained from the hydrolysis of starch
Maltose
Can disaccharides be absorbed by the human digestive system?
No
______ ______ break disaccharides apart into monosaccharides
digestive enzymes
3 important polysaccharides
Starch
Cellulose
Glycogen
Alpha glucose units
How glucose is stored in plants
Two main forms - amylose & amylopectin
Used by plants and herbivores as fuel
Starch
Beta glucose units
Major component of woody plants and fibers
Rigid and insoluble in water
Humans can’t break this down
Cellulose
Also called animal starch
Main carbohydrate store in animals
Found in muscles and liver
Glycogen
Organic molecules that are insoluble in water but soluble in nonpolar solvents
Lipids
Functions of lipids
Energy Protection and insulation Cell membrane structure Hormones Vitamins
4 main groups of lipids
Fatty acids
Glycerides
Nonglyceride lipids
Complex lipids
Only single carbon bonds Stack in a regular closely packed structure Strong interactions between chains High melting points Solid at room temp Mainly obtained from animal sources Called "fats" Found in meats, whole milk, butter, cheese, etc.
Saturated fatty acids
Contain one or more cis double bonds Cis bonds "kink" the chain so they cannot pack closely Few attractions between chains Low melting points Liquids at room temperature Mainly obtained from plant sources Called "oils" Found in olives, safflowers, corn, etc.
Unsaturated fatty acids
What does “essential” mean in essential fatty acids?
It means that they cannot be produced In the body
Fatty acids react with alcohols to form esters and water
Esterification
10 carbons
decanoic acid
12 carbons
dodecanoic acid
14 carbons
tetradecanoic acid
16 carbons
hexadecanoic acid
18 carbons
octadecanoic acid
20 carbons
eicosanoic acid
Hydrogen added to both sides of double bond in unsaturated fatty acids
hydrogenation
One fatty acid on glycerol
monoglycerides
two fatty acids on glycerol
diglycerides
three fatty acids on glycerol
triglycerides
Formed from glycerol plus 3 fatty acids
triglycerides
Esters formed from glycerol and fatty acids
glycerides
Bad cholesterol
LDL
Good cholesterol
HDL
Esters of saturated fatty acids and long-chain alcohols
Waxes
Lipids not derived from glycerol
Nonglyceride lipids
Base hydrolysis of a fatty acid ester
Often used to make soap
Saponification
Opposite process of esterification
Acid hydrolysis
Structural components of cell membranes
Sphingolipids
A steroid nucleus plus an 8-10 carbon side chain and OH group
Found in animal fats and vegetable oils
Sterols
What does a steroid look like?
3 cyclohexane and 1 cyclopentane
What is the most abundant steroid in the body?
Cholesterol
What is cholesterol needed for?
Cell membranes, brain and nerve tissue, steroid hormones, and Vitamin D
Lipids bonded to other types of molecules
Complex lipids
Consist of both proteins and lipids
Lipoproteins
Contain one or more phosphate groups
Phospholipids
Contain both proteins and lipids
Lipoproteins
What does it mean to be an emulsifier?
Help transport of nonpolar lipids in polar body fluids
Lipids plus one or more phosphate groups
Phospholipids
Carry triglycerides synthesized in liver to tissues for storage
VLDL - very low density lipoproteins
Phospholipids are the main component of ____ ______
cell membranes
Polar “head” on outside and inside of cell
Nonpolar “tail” between the layers
Lipid bilayer
Approximately 50% of the dry weight of the body consists of ______
proteins
Functions of proteins
Structural - provide support Contractile - aid in motion Transport - carry substances through the body Storage - store nutrients Hormone - regulate chemical reactions Enzyme - catalyze biochemical reactions
R groups are alkyl groups
Hydrophobic - repel water
Nonpolar
R groups contain polar functional groups like alcohols, thiols and amines
Hydrophillic - attract water
Polar
R groups contain carboxylic acid
Acidic
R groups contain amino groups
Basic
The different _ ____ determine the different amino acids
R groups
Sequence of amino acids in the peptide chain
Any modification of this structure may lead to congenital defects
Primary protein structure
Shape the chain adopts
Secondary protein structure
Three dimensional shape of the molecule
Tertiary protein structure
Interaction of multiple polypeptide units
Quaternary protein structure
What are the tertiary shapes of proteins?
Globular and fibrous
Most common shapes of secondary protein structure
Alpha helix and beta pleated sheet
What is denaturation
Loss of structure by a protein
4 factors that can cause denaturation
Heat
pH changes
Organic compounds
Mechanical agitation
Oxidation-reduction reactions
Oxidoreductases
Transfer of groups between compounds
Transferases
Hydrolysis reactions
Hydrolases
Reactions involving double bonds
Lyases
Molecular rearrangement
Isomerases
Formation of chemical bonds
Ligases
Only specific shaped substrates fit into the specific shaped enzyme
Lock and key
Both the enzyme active site and substrate adjust shapes to align better
Different substrates won’t cause this change to occur
Induced fit
The place on an enzyme where the substrate binds and the reaction occurs
Active site
Factors affecting enzyme activity
Temperature
pH
Concentration
Inhibitors
Similar structure to substrate and competes for active site
Competitive inhibitors
Binds to the enzyme somewhere other than active site
Distorts enzyme shape so real substrate no longer fits
Noncompetitive inhibitors
The chemical reactions organisms need to survive
Metabolism
Complex molecules broken down to simpler ones
Energy is released
Catabolism
Large molecules built from simple molecules
Energy is absorbed
Anabolism
Stages of Metabolism
Digestion
Glycolysis
Citric Acid Cycle
Electron Transport Chain
Carbohydrates are broken down into what?
simple sugars (mainly glucose)
Lipids are broken down into what?
Fatty acids and glycerol
Proteins are broken down into what?
Amino acids
The chemical reactions involved in metabolism are organized into what?
Metabolic pathways
Where does digestion occur?
Mouth, stomach and small intestine
A 10-step process that begins the breakdown of glucose from:
one 6-carbon glucose molecule to two 3-carbon molecules of pyruvate
Glycolysis
Glycolysis can be broken down into two phases:
Energy investment and energy payoff
Reactions 1-5 in glycolysis
2 ATP “spent”
Energy investment
Reactions 6-10 in glycolysis
4 ATP produced
Energy payoff
1 complete turn of the citric acid cycle produces:
1 ATP
3 NADH
1 FADH2
Pyruvate migrates to mitochondria where the next stage of metabolism occurs
Citric acid cycle
The electron transport chain produces:
32 ATP (plus water)
How much ATP is produced from 1 glucose molecule
36