IB HL Bio Unit 3 - Macromolecule Terms

Carbon

Tetravalent element that serves as the building block of life. Present in all four Macromolecules

Organic (Carbon) Chemistry

The study of compounds containing carbon

Polar Covalent Bonds

A Covalent Bond where the two atoms have different electronegativities, resulting on unequal pulls on the electrons

One side = (+) while the other is (-)

Nonpolar covalent bonds

A Covalent Bond where the two atoms have the same/close electronegativities, resulting in an equal pull on the electrons.

Electronegativity

The tendency of an atom to attract shared electrons

Hydrogen Bond

A polar bond between hydrogen and another atom

Valence Electrons

Electrons that occupy the outer-most shell of an atom

Valence

The number of covalent bonds an atom can form

Tetravalence

The ability to form 4 covalent bonds total - why carbon is the “backbone for life”

Hydrocarbon

A compound of only carbon and hydrogen

Hydroxyl

Functional Group (OH)

Carboxyl

Functional Group (COOH)

Amino

Functional Group (NH2)

Phosphate

Functional Group (PO4 3-)

Macromolecules

Nucleic Acids, Lipids, Proteins, Carbohydrates

Metabolism

Chemical reactions in a cell

Anabolic

an Endergonic Metabolic pathway that synthesizes Polymers from Monomers through dehydration synthesis

Endergonic

stores/requires energy

Condensation reaction

Takes place during anabolic pathways - takes out water to combine molecules

Catabolic

an Exergonic Metabolic pathway that breaks down Polymers into Monomers through hydrolysis

Exergonic

releases energy

Hydrolysis

Takes place during catabolic pathways - inserts water to break apart molecules

Monomer

individual molecules that make up a polymer

Polymer

A large molecule consisting of monomers

Nucleic Acid Elements

CHONP (Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous)

Nucleic Acid Monomer

Nucleotide

Nucleic Acid Polymer

Polynucleotide

Nucleic Acid Bond

Phosphodiester Bond

Proteins Elements

CHON (Carbon, Hydrogen, Oxygen, Nitrogen - SOMETIMES SULFUR)

Proteins Monomer

Amino Acids

Proteins Polymer

Polypeptides - there are 20 total

Proteins Bond

Peptide Bond

Carbohydrates Elements

CHO

Carbohydrates ratio

1:2:1

Carbohydrates Monomer

Monosaccharide - simple sugars

Carbohydrates Polymer

Polysaccharide - complex carbs

Pentose

5 carbons - ex. Ribose

Hexose

6 carbons - ex. Glucose, Galactose, Fructose

Alpha Glucose

-OH is below the ring

Alpha Glucose glycosidic linkages are more easily digested by humans

Beta Glucose

-OH is above the ring

humans cannot break beta glucose glycosidic linkages = pass through as fiber.

but COWS have a symbiotic relationship with stomach bacteria that can break down beta glucose bonds (cellulose)

Glucose function

POLAR (lots of OH bonds) - soluable in water = transported through blood plasma

STABLE (ring form) - great material for building polysaccharides like Starch, Glycogen, and Cellulose

OXIDIZED - ATP energy for cellular respiration

Cellular Respiration

When Glucose is oxidized to create ATP energy for the cell

Polysaccharides Function

Energy storage (ex. Starch and Glycogen) and Structural building material (ex. Cellulose and Chitin)

Disaccharide

2 monosaccharides joined through condensation reaction with Glycosidic Linkages

Sucrose

Glucose + Fructose

Lactose

Glucose + Galactose

Maltose

Glucose + Glucose

Glycosidic Linkage

covalent bond formed with condensation reaction connected with an oxygen

4 major Polysaccharides

Starch, Glycogen, Cellulose, Chitin

Starch

FUNCTION - Energy Storage

FOUND IN - Plants

MONOMER - alpha glucose - Amylose (linear/coiled polysaccharide) + Amylopectin (very branched polysaccharide - BETTER FOR ENERGY STORAGE)

SOLUBILITY - large molecule = relatively insoluble

Glycogen

FUNCTION - Energy Storage

FOUND IN - Animals - large amounts in liver + muscles in humans

MONOMER - alpha glucose - highly branched

SOLUBILITY - relatively insoluble

Cellulose

FUNCTION - Structural Material

FOUND IN - Plants - cell walls

MONOMER - beta glucose - linear

BONDS - linked with hydrogen bonds to form bundles called cellulose microfibrils

Chitin

FUNCTION - Structural Material

FOUND IN - Fungi - cell walls, and Anthropods - exoskeleton

MONOMER - modified glucose

Also used as surgical thread

Glycoproteins

A sugar-protein molecule embedded in cell membrane as “ID Tag"

• cellular recognition/communication

  • receptors/secretion of chemical signals

• structural support

• Ex. ABO Blood Groups

• work as antigens

Glycoproteins - ABO Blood Groups

prescence of specific glycoproteins - determines ABO blood typing system

Lipids Elements

CHO (Carbon, Hydrogen, Oxygen) - VERY little O compared to C

Lipids Unifying Properties

No real monomers/polymers

Defined by Hydrophobic properties as they have long hydrocarbon chains and little Oxygen

Hydrophobic

insoluble/repels water - nonpolar

Hydrophilic

soluble/”likes” water - polar

Amphipathic

Contains both hydrophilic and hydrophobic parts in the structure

Lipids Triglycerides

Fats and Oils - made of two building blocks (NOT MONOMERS) - one glycerol and 3 fatty acid chains connected by Ester Linkages

Glycerol

A 3-carbon alcohol w/ 3 Carboxyl groups (COH)

each -OH group is a location for the fatty acid to attach to in Triglycerides

Fatty Acids

Long Hydrocarbon chains that are either Saturated, Monounsaturated, Polyunsaturated, or Trans-unsaturated, connecting to Glycerol in Triglycerides

Saturated Fatty Acid (fats)

BONDS: All single bonds = linear w/ no kinks = easily packed together

MELTING POINT: high, solid at room temp

FOUND IN: mammals (lard)

Monounsaturated Fatty Acid

One double-bonded carbon in the hydrocarbon chain that creates a bent configuration

Polyunsaturated Fatty Acid

2+ double-bonded carbons in the hydrocarbon chain that create multiple bends in the configuration

Cis-unsaturated Fatty Acid (oils)

BONDS: double bonds = bent configuration

MELTING POINT: low, liquid at room temp

FOUND IN: fish and plants (ex. olive oil)

Trans-unsaturated Fatty Acid (trans fats)

An unnatural, factory-produced formation of a fatty acid that undergoes hydrogenation to put both hydrogens on an unsaturated fatty acid on the different sides, removing kinks and making them function more similarly to saturated fatty acids but can increase cholesterol

Lipids Fats and Oils Functions

• Longer-term energy storage than carbohydrates

• Insulation to reduce heat loss

• Protection/cushioning/support of internal organs

• Mammals store Fats in adipose tissue

Adipose Tissue

Cell comprised mostly of a fat reservoir that is broken down to provide atp energy for the endotherms

Endotherms

Regulate body temp - requires constant energy from fats in adipose tissue

Lipid storage in plants and seeds

A greater amount of fats and oils provide energy for the seed when photosynthesis is unavailable

Phospholipids

Provides flexibility as part of the phospholipid bilayer of cells comprised of one glycerol and phosphate with two fatty acid tails, bonded with ester linkages

Phospholipid Hydrophilic Head

• A glycerol and a phosphate

• “loves” water

• faces the outside of the phospholipid bilayer

Phospholipid Hydrophobic Tails

• Two fatty acid tails - saturated and unsaturated

• “hates” water

• on the middle of the phospholipid bilayer

Phospholipid Bilayer

Two layers of Phospholipids that form the cell membrane and provide flexibility

• Hydrophilic heads face the aqueous environments on the inside and outside of cells

• Hydrophobic tails remain in between the two heads, away from both aqueous environments

Ester Linkage

Part of Lipids - covalent bond between a hydrogen and acidic hydroxyl group

Lipids Steroids

• 4 fused hydrocarbon rings

• different functional groups are added to ring framework to give different properties.

• Hydrophobic and insoluble = can pass through cell membrane

• low proportion of oxygen to carbon

Cholesterol

Part of animal cell membranes

• reduces permeability of cell membrane by reducing fluidity @ higher temperatures

• increases permeability of cell membrane by increasing fluidity @ lower temperatures

• also modified into other steroids (hormones)

Hormones

• controls a wide range of physiological functions

• modified cholesterol molecules

• hydrophobic = easily pass through cell membrane to give cell instructions

• ex. testosterone + oestrogen (estrogen)

Lipids Waxes

Diverse lipids that are typically long hydrocarbon chains

• Melt @ low temperature (think candle)

• energy storage

• Used to “water proof” due to hydrophobic tendencies

  • ex. waxy sheath on plants to control evaporation and hydration

Proteins functions

• enzymes (lactase)

• hormones (insulin)

• transport (haemoglobin)

• structure (collagen)

• movement (actin)

• storage (ovalbunim)

• defense (antibodies)

• receptors (rhodopsin)

Proteins elements

CHON (Carbon, Hydrogen, Oxygen, Nitrogen) plus additional side chain elements

Proteins Monomer

Amino Acid

• Amino Group (NH2)

• Carboxyl group (COOH)

• Alpha carbon

• Side chain/R group

Proteins Non-essential Amino Acids

Humans are able to make non-essential amino acids from other amino acids

Proteins Essential Amino Acids

Humans are unable to make essential amino acids = must be from food

*Vegan/Vegetarian Issues - best source of essential amino acids = animal proteins (beef, poultry, eggs), and restricting these is risky

Proteins Dipeptide

Two Amino Acids held together via a peptide bond

Proteins Peptide Bond

Resulting from a condensation reaction connecting the carboxyl group with the amino group by removing a water molecule

Proteins Side Chain

Variable - Provides property to amino acid. 20 different side chains = 20 different amino acids

• Nonpolar side chain = hydrophobic

• Polar side chain = hydrophilic

• Charged side chain = hydrophobic, acidic or basic

Proteins Polypeptide

Chains of amino acids linked by Peptide bonds, with a c-terminus (carboxyl end) and n-terminus (amino end) and an N-C-C backbone

Protein vs. Polypeptide

A Polypeptide is a chain of 3+ amino acids, and is the polymer of proteins, which are 1 or more polypeptides

Lysozyme

An enzyme in tears and saliva able to kill certain bacteria

Glucagon

a hormone that raises blood sugar levels (opposite to insulin)

Myoglobin

An oxygen-binding protein in muscles

Alpha-nuerotoxins

Group of neurotoxins found in snake venom

Conjugated Proteins

Contains a non-protein component

ex. Haemoglobin and Glycoproteins

Non-Conjugated Proteins

Contains only polypeptides (ex. insulin and collagen)

Integral Proteins

Embedded into the phospholipid bilayer of a cell membrane, with the hydrophobic side chain embedded into the hydrophobic tails of the phospholipids

Fibrous Proteins

• Long, skinny, simple strands of repeating structure

• strength + stability (structural support)

• Insoluble in water

• ex. Collagen

Globular Proteins

• spherical and complex with irregular folds

• soluble in water

• found in enzymes, transporters, and regulators

• ex. Insulin