Unit 1 - Chemistry of Life

Polar molecule

opposite charges

Hydrophilic

Molecules that dissolve in water

Hydrophobic

Nonpolar molecules that do not dissolve in water

Cohesion

Water’s ability to hydrogen bond with other molecules of water

What property is responsible for water’s high surface tension?

Cohesion

Adhesion

Water’s ability to stick to other molecules + surfaces

Temperature moderation

Water’s high specific heat allows it to absorb lots of energy without increasing as much in temperature

Expansion upon freezing

H-bonds between waters spread out at low temps

Which property allows ice to float on water

Expansion upon freezing

Versatile solvent

Water is the solvent of life (all biochem reactions occur in aqueous solution)

When ionic substance dissolved in water, each ion surrounded by

Hydration shell (H₂Os around it)

Water’s properties (5)

• Cohesion

• Adhesion

• Temperature moderation

• Expansion upon freezing

• Versatile solvent

Living things composed of

Organic compounds (containing carbon)

Organic compounds composed of

Hydrocarbons

Hydrocarbons made of

Covalently bonded carbons (tetravalent), bonded to hydrogens

What is it called when hydrocarbons can vary in arrangement while having the same chemical formulas?

Isomers

Isomer types (3)

Structural - different arrangement of ATOMS

Cis-trans - different arrangement of atoms around DOUBLE BONDS

Enantiomers - Isomers which are mirror images of each other around central carbon

Functional Groups

Molecular substituents that affect the molecule’s function when attached to a hydrocarbon

Biological Macromolecules

Carbs, lipids, proteins, nucleic acids

What do Carbs, lipids, proteins, nucleic acids all contain

Carbon, Hydrogen, Oxygen

What element do only proteins + nucleic acids contain

Nitrogen

What element do only nucleic acids + phospholipids contain

Phosphorous

Which bio macromolecule is not a polymer

lipids

Dehydration Synthesis

Joins monomers together by removing hydrogen atom from one, hydroxyl from other → creating H2O through covalent bond

Hydrolysis

Separates monomers by adding H2O to break covalent bond

Carbohydrates function

Used for energy + building material

Simplest-ratio formula of carbs

CH₂O

Complex carbs

Many polysaccharide polymers of sugar/monosaccharide monomers

Monosaccharides (2, bond + structure)

Held by covalent bonds

structure can change (linear, branched, coiled) to change function

2 Types of polysaccharides

Storage polysaccharides = future energy usage

Structural polysaccharides = building material

Glycogen

Coiled, Storage carb for animals

Starch

Coiled, Storage carb for plants

Cellulose

Linear, Structural carb in plant cell walls

Chitin

Linear, Structural carb in animals

Lipids definition

Nonpolar macromolecules (not polymers)

Lipids composed of

Glycerol → 3 carbon alcohol

Fatty acids → hydrocarbons with a carboxyl group

What impacts the function of a lipid

It’s fatty acid structure

2 types of fatty acid structure

Saturated = single bonds in hydrocarbon chain (linear structure)

Unsaturated = at least 1 double bond in hydrocarbon chain (kinked structure)

Phospholipids

• Hydrophilic phosphate head and 2 hydrophobic fatty acid tails separated by glycerol

• Head is polar, tails are nonpolar

Phospholipid bilayer

Phospholipids: In aqueous solutions, tails orient away from water and heads toward water

Steroids (polarity + description)

Nonpolar molecules with 4 fused carbon rings

• Testosterone, estrogen, cholesterol

Nucleic Acids/polynucleotides (monomer + function)

Nucleotide monomers

Sequence encodes genetic info

Gene

section of DNA

Nucleotide made of

Phosphate group

Pentose sugar

Nitrogenous base

DNA Nucleotides Contain:

Deoxyribose sugar

1 of the following: adenine, thymine, cytosine, guanine

RNA Nucleotides Contain:

Ribose sugar

1 of the following: adenine, uracil, cytosine, guanine

DNA:

Double stranded

Codes for proteins to be manufactured in the cell

RNA:

Single stranded

mRNA → message to a ribosome, specifying amino acid sequence

tRNA → bonds to amino acids + transfers into ribosomes during protein synthesis

rNA → ribosomes

Proteins

1 or more polypeptides in 3D shape, composed of amino acid monomers

Amino acid

Central carbon atom C-bonded to:

• Amine functional group

• Hydrogen atom

• Carboxyl group

• R-group

How many amino acids are there

20

R-group

Variable group that dictates molecular behavior of each amino acid (determines polarity)

Directionality of Amino Acids:

N-terminus at amine end (start)

C-terminus at carboxyl end (end)

Dehydration Synthesis of Amino Acids

C-terminus of 1 amino acid loses hydroxyl group

N-terminus of another amino acid loses hydrogen atom

This forms covalent peptide bond

Amino acids bond together, form polypeptide chain (primary structure)

R-groups in primary structure interact + determine structure/function overall

Primary structure

amino acid sequence linked by peptide bonds

Polypeptide backbone

Secondary structure:

Alpha-helices, beta-pleated sheets form bcs Hydrogen bonds between carbonyl/amine groups in polypeptide backbone

Tertiary Structure:

Functional groups of R-groups interact

Forms 3D structure

Quaternary Structure:

More than 1 tertiary structure binds to another polypeptide

Where is the lipid bilayer found

Plasma, cell membrane

Fats function

Provide energy storage + cell function

• Can provide insultation in mammals

Steroid structure

Nonpolar molecule —> 4 fused carbon rings

Examples of steroids + functions

Testosterone, estrogen, growth, development, energy, metabolism, homeostasis

Triglycerides

fats + oils

Glycerol backbone + 3 fatty acid chains

4 types of lipids

Triglycerides

Steroids

Waxes

Phospholipids

Amine functional group formula

NH₂

Carboxyl group formula

COOH

Tertiary structure interaction types

Hydrogen bonds

Hydrophobic

Hydrophilic

Ionic

Disulfide

Hydrogen vs Covalent vs Ionic bonding

Ionic —> 1 atom transfers >/= 1 electron to another atom (intramolecular)

Covalent —> 2 atoms share pairs of electrons to fill outer valence shells (intramolecular)

Hydrogen —> Attraction between hydrogen covalently bonded to one electronegative atom and another electronegative atom (intermolecular —> between molecules not atoms)

When does dehydration synthesis take place

When building polymers (carbs, proteins, nucleic acids)

Phosphate group

Functional group in

ATP (energy exchange)

DNA

Methyl group

Functional group

Silences DNA

makes molecules nonpolar (hydrophobic)

Hydroxyl, Carbonyl

Functional group

Makes molecules hydrophilic/water-soluble

Sulfhydryl group

Functional group

Bends proteins into specific shapes

Carboxyl, amino groups

Functional groups

Amino acids

Acetyl group

Functional group

Makes DNA available for gene expression

How do plants/animals receive glucose monomers in carbs

Hydrolysis of bonds connecting monomers in the polysaccharide

Tertiary

2 - Hydrogen

3 - Covalent

4 - Hydrophobic

5 - Ionic

Which sugar carbon is phosphate group and nitrogenous base connected to

Phosphate - 5’ C

Nitrogenous base - 1’ C

New DNA nucleotides added to which end

3’

What type of bond connects complementary nitrogenous bases

Hydrogen bonds

Is dehydration synthesis anabolic or catabolic

Anabolic

Is hydrolysis catabolic or anabolic

catabolic