U4AOS2 - Key food molecules Flashcards
Definition of Amino Acids (inc. alpha-amino-acids, chirality, key chemical process)
Building blocks of proteins
Alpha-Amino Acids:
- also referred to as 2-amino-acids
- has a central carbon, bound directly to the carboxyl and amino functional groups
- can be chiral if R is not a lone hydrogen
Amino acids often undergo condensation
Purpose of Amino Acids
to balance the pH in the body by reacting with the excess H+ or OH-
Similar principle to LCP - partially opposes the change, tries to return the body to the correct pH
Properties of Amino Acids in Acids
NH2 group(s) accepts a proton/hydrogen (acting as a base) to form NH3+
Will become a cation
Properties of Amino Acids in Bases
COOH group(s) donates a proton/hydrogen (acting as an acid) to form COO-
Will become an anion
Solubility of Amino Acids (in water)
Soluble in water - as a result of the polar amino and carboxyl groups (from neutral pH)
Essential Amino Acids
Amino Acids that cannot be synthesized (produced) by the body, but instead - must be consumed in diet
Non-Essential Amino Acids
Amino Acids that can be synthesized by the human body - do not need to be supplemented through diet
Properties of Amino Acids in Neutral Solutions (inc. name & overall charge)
The Amino Acid will act as an acid and a base:
NH2 group(s) will become NH3+ <strong>AND</strong> COOH group(s) will become COO-
Referred to as a zwitterion
Overall charge, typically 0, but if the R chain contains NH2 (amino) or COOH (carboxyl) then the overall charge may be different
Formation of Peptides (inc. name of functional group produced)
Condensation Reactions between Amino Acids
An amino group from one amino acid will react with the carbonyl group, creating an amide link (or peptide link - but only if it’s actually a protein)
(and producing a water)
Note - order matters with peptides, Aly-Gly and Gly-Ala are different
Dipeptides
Two 2-amino-acids combined
Polypeptides (inc. specific name of reaction that creates them)
Many 2-amino-acids combined
Created through condensation polymerization
Primary Proteins (inc. structure & bonding)
Very large polypeptides
There will always be a carboxyl terminal and amino terminal.
Bonding is covalent intramolecular - through the amide link
Secondary Proteins (inc. bonding & types of structures)
Hydrogen bonding between the amide links of a single protein
Tertiary Proteins (inc bonding, importance of this form)
Bonding between R-chains
<strong>ADD TYPES</strong>
This is the functional form of a protein - if the tertiary structure is disrupted - the protein will lose its function
Quaternary Proteins
Combinations and interactions between two or more tertiary proteins
Intermolecular bonds between side chains R
Structure of Carbohydates (inc. general formula)
Large amounts of carbon, hydrogen and oxygen
General Formula: Ca(H2O)b
This means that carbohydrates will have very high densities of oxygen (higher than alcohols etc)
Monosaccharides (inc. form & inter bonding)
Smallest building blocks of carbohydrates
Exist in a straight-chain form or cyclic forms, however, in aqueous solutions, the cyclic form predominates
Theyre polar and soluble in water (due to hydroxyl groups)
Alpha vs Beta Monosacchardies
Examples of Monosaccharides (3)
Glucose & Fructose (which exist in fruits and living systems)
Galactose (found as a breakdown of lactose)
Disaccharides (inc. form & name of functional group)
(also called two ring sugars)
Links two Monosaccharides together with a condensation reaction (producing water)
Creates a glycosidic linkage (or ether) between the two monosaccharides
Formula & Molar Mass of Glucose
C6H12O6
MM: 180
Examples of Disaccharides (3)
Sucrose (alpha-glucose + beta-fructose - used in fruits)
Maltose (2x alpha-glucose)
Lactose (glucose + galactose - found milk)
Polysaccharides (inc. production)
(complex carbohydrates)
Made up of many individual monosacchardies
Creates a glycosidic linkage (or ether) between the each monosaccharide (polymer) - and releases a water for every unit added
Amylose (inc monomer, structure, intermolecular forces, enzyme)
Type of Starch
Uses α-glucose as its monomer
CH2OH points in the same direction & no branching (results in a tightly coiled helices)
Strong intermolecular forces (packed close together - but not locked like cellulose)
Enzyme for Hydrolysis: Amylase, then Maltase
Cellulose (inc monomer, structure, intermolecular forces, enzyme)
Uses β-glucose as its monomer
Used as the cell wall for plants
CH2OH points opposite directions (allows them to lock into each other) & No Branching
Very strong intermolecular forces (tightly packed)
Enzyme for Hydrolysis: Cellulase (not produced by humans)
Amylopectin (inc monomer, structure, intermolecular forces, enzyme)
Type of Starch
Uses α-glucose as its monomer
CH2OH points in the same direction & branching (roughly every 20 units)
Weaker intermolecular forces (not packed close together)
Enzyme for Hydrolysis: Amylase, then Maltase
Glycogen (inc monomer, structure, intermolecular forces)
Used for energy storage in the body (formed from glucose)
Uses α-glucose as its monomer
CH2OH points in the same direction & branching (roughly every 10 units)
Weaker intermolecular forces (not packed close together)
Solubility of Carbohydrates in Water
Soluble in water, due to the carboxyl groups
However - the more branching - the greater the surface area of the carboxyl groups, so its more soluble
Storage of excess Glucose
It’ll be converted to glycogen and stored in muscles and the liver
the body will then reconvert to glucose when required
Artificial Sweeteners (inc. name, GI index, energy content, relative sweetness)
Aspartame, artificial sweetener - not a protein or carbohydrate
Has a GI index of 0 (compared to glucose’s 100)
Has the same energy content to glucose
Relative sweetness of 200, compared to glucose’s 0.74
Triglycerides (inc. structure, formation, intermolec bonding)
Type of lipid, the form of fats or oils in the body
Structure: Has a glycerol backbone, and 3 fatty acids (different or same), connected with an ester in the middle
Formation: formed through condensation reactions, with 3H2O released
Intermolecular Bonding: mostly non-polar
Fatty Acid (inc. structure & how to name)
Building blocks of proteins
Structure: linear carbon chain (single or double bonds), with a carboxyl group on the end
Naming: make sure to add ‘acid’ after the name of the fatty acid from the databook
Saturated Fatty Acids (inc. IRL example, effect on melting point)
Only single carbon-carbon bonds
IRL example: butter
Effect on melting point: no C=C means packed closer together, therefore, stronger intermolec bonds, higher melting point
Unsaturated Fatty Acids (both types, effect on melting point)
Contains double carbon-carbon bonds
Mono-unsaturated - only one carbon-carbon double bond
Poly-unsaturated - more than one carbon-carbon double bond
Effect on melting point: C=C means ‘kinks’ in chain, not packed as close together (as saturated), therefore, weaker intermolec bonds, lower melting point - this effect is ‘stackable’ - 2 C=C will have lower melting point than 1 C=C
Omega-3 vs Omega-6 Fatty Acids (inc. omega carbon)
Omega Carbon: Carbon atom on the methyl group
Omega-3: when the carbon-carbon double bond is on the 3rd carbon relative to the omega carbon
Omega-6: when the carbon-carbon double bond is on the 6th carbon relative to the omega carbon
Non-Essential Fatty Acids
Can be synthesized by the human body - don’t need to include in our diet
Essential Fatty Acids
Cannot be synthesized in the human body - need to include in our diet
Effect of increasing the number of carbons in fatty acids on melting point
More carbons increase the dispersion force.
Increased intermolec bonds -> higher melting point
Fats vs Oils - with reference to melting point
Fats - solids @ room temp (usually saturated fatty-acids)
Oiis - liquids @ room temp (usually unsaturated fatty-acids)
What are Vitamins (+essential/nonessential)
Organic Compounds that are required for the body to function properly
All vitamins are essential, must be consumed in diet (with the exception of VitD which is synthesized through sunlight, non-essential)
Water Soluble Vitamins (Structure, Solubility, Storage, Consumption)
Predominantly Polar Functional Groups
Soluble in Water (Hydrogen Bonding)
Surplus will be excreted if not consumed (often through urine)
Therefore, must be consumed regularly
Fat Soluble Vitamins (Structure, Solubility, Storage, Consumption)
Vitamins ADEK
Predominantly Non-Polar Functional Groups
Soluble in Fat (dispersion forces)
Surplus will be stored in fatty issues (for a long time i.e. an adult can store several years worth of VitA supply)
Therefore, can be consumed less often, and if its consumed too quickly, it can be dangerous (as the body cannot dispose of the excess - the conc. can increase too high)
