● Water and Hydrogen Bonding
○ Water is a polar molecule
■ Unequal electron sharing btwen o and h (partial negative and partial
positive region)
■ Hydrogen bonds : intermolecular bond (in between molecules)
■ Oxygen is partially neg H = partially positive
● H bond - weak bond in between those areas
○ Most weak bond than intramolecular bonds
■ H bonds are everywhere and essential
● Hold together DNA
● Nucleic acid, protein,
○ Cohesion: between water molecules
■ Responsible for high heat of vaporization, high specific heat, high surface
tension - water holding head
○ Adhesion: water sticking to other stuff(polar molecules)
■ Transpiration
● Water cohere to other molecules and adhere to the sides of the
plants as it evaporates from the top
○ Surface tension
■ Force exerted by the water molecules on the surface of water; web/net
upon the surface
■
○ Acidic Solution: solutions with more H+ ions than OH- ions (hydrogen than
hydroxide ions) - pushes the ph DOWN
○ Basic solution: more OH- ions than H+ ions Ph higher up
Elements of Life
●
○ CHNOPS (carbon hydrogen nitrogen oxygen phosphorous sulfur)
■ Carbon - makes up everything
■ Hydrogen - energy exchange (NAD+ -- NADH) (low to high energy)
● Pumped around to create energy gradients
■ Phosporous - phosphate groups in ATP
● Monomers, polymers etc
○ M onomers - carbohydrates, proteins and nucleic acids are built from building
blocks called monomers
○ Living things -- macromolecules with 3D shapes and functions combing
monomers to make polymers
■ STRUCTURE DETERMINES FUNCTION
○ Dehydration synthesis:
■ Removing Water
■ Enzymes pull out a OH and H out of two monomers (water) is pulled out
amd creates a bond
■
○ Hydrolysis
■ Adding a water to break apart a polymer to make a monomer
○ Things you may want to know about functional groups
■ Phosphates - energy exchange
■ Methyl group - silence DNA
■ Polar function groups:
● hydroxyl/carbonym - hydrophilic and water soluble
■ Carboxyl and amino - works with amino acids
■ Sulfhydril - protein structure
■ Acetyl group - activate DNA
Carbohydrates and Lipids
●
○ Four types of Macromolecules make up living organisms
■ Disaccharide (sugar) - carbohydrates
■ Phospholipid - lipid
■ Hemoglobin - protein
■ DNA- nucleic acid
○ Carbohydrates:
■ Monoscaharides (monomers) - simple sugars : energy sources and
building blocks
■ Disaccharides: two lined monosaccharides (polymer) : energy transfer
● Ex: sucrose/lactose
■ Polysacharides: energy storage (starch (plants) and glycogen)
● Cellulose- cell walls
● S ome animals can digest cellulose (not humans) -- hard to
hydrolize the bonds
○ Linked glycoses (linked in a way where enzymes cant
break it down to free the monomers -- humans)
■ Some anymals can (termites) developing symbiotic
relationship w/ microorganisms to hydrolyze
cellulose into glucose
● Humans can break down starch -- glucose to power cellular
respiration
Lactose tolerance/intolerance
■
● Lactose: sugar in milk (dissacharide)
● Lactase: hydrolizes lactose into monosaccharides
● Mammals produce lactase during infancy (suckling)
○ Only time mammals drink milk
● Adult mammals dont produce lactase (why produce enzyme for
something u dont eat
● Some groups (humans) evolved lactase persistence
○ Developed a mutation to continue to produce that lactase
enzyme - niche of exploitation of food only happened
○ Majority of humans are lactose intolerant (lactaid - an
enzyme to break down lactose and be able to digest)
● Lipids
○ Lipids: molecules that are wholly or partially nonpolar
■ Dont dissolve in water - hydrophobic
○ Not composed of repeating monomers (subunits) but not constantly repeated
○ Functions:
■ Fat (triglycerides): energy storage
■ Wax: waterproofing
■ Membrane Formation (phospholipids)
■ Signaling (Steroids)
