BIO12 - BIOLOGICAL MOLECULES

What is a biological molecule? (1)

• Chemical compounds in living organisms

  • Building component of life (found in food)

What are the 4 main groups of biological molecules in the body? (4)

• Carbohydrates

• Lipids

• Proteins

• Nucleic acid

How are most compounds formed? (4)

• Monomers → polymers

  • CLPN are polymers

• Monomers = single substance

• Creation of polymers = synthesis

• Destruction of polymers = hydrolysis

Synthesis (3)

• H⁺ from molec1 binds w/ OH^- from molec2

• Forms H₂O + breaks bond (dehydration)

• Polymers bind together

Hydrolysis (2)

• H₂O dissociates into ions

• Each ion attaches to a diff. monomer from a single chain

  • Breaks polymer apart

Role of carbohydrates (3)

• Primary kJ source for body

  • Mostly ingested via plants

HOW WE GET GLUCOSE

• Plants make glucose via photosynthesis (chloroplast)

  • 6CO₂ + 6H₂O + kJ → C₆H₁₂O₆ + 6O₂

• Body makes kJ with glucose via cellular respiration

  • C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + kJ (ATP)

Properties of carbohydrates (3)

• Empirical formula = CH₂O

  • C = carbo

  • H₂O = hydrate

• “-ose” suffix = sugar

  • Ex. glucose, ribose, lactose, amylose

• Usually polar → dissolves in water

  • Hydrophilic

3 main types of carbohydrates (1) (2) (2) (2)

• ALL get broken down into monosaccharides when digested

MONOSACCHARIDES

• Single sugar molec

• Ex. Glucose, Fructose, Galactose

DISACCHARIDES

• Paired sugar molecs

  • Made up of two monosaccharides

• Ex. Maltose, Sucrose, Lactose

POLYSACCHARIDES

• 10+ sugar molecs

• Ex. Starch, Glycogen, Cellulose

Monosaccharides (4)

• Single monomer

  • Ex. Glucose, Fructose, Galactose

• In chain/ring structure

• Glucose + Fructose = isomers

  • SAME formula, DIFF. shape

• Diff. chemical properties b/c diff. functional groups

  • Ex. Fructose = sweeter than glucose

Disaccharides (4)

• 2 monosaccharides together

• Glucose + Fructose = Surcrose

• Glucose + Glucose = Maltose

• Glucose + Galactose = Lactose

Types of polysaccharides (3)

• Starch

• Cellulose (fiber)

• Glycogen

Starch (3)

• Plants = main source

• Stored as glucose (kJ) in plants

• Little to none side branches

Cellulose (3)

• Insoluble

  • Hard to digest

• Main component of cell wall

• Long, linear, unbranched chains

  • Forms H-bonds w/ nearby chains

Glycogen (3)

• Stored as glucose (kJ) in animals

• Stored in liver + muscle cells

  • Saves kJ for blood sugar drops (homeostasis mech)

• Short/highly branched

What are lipids? (1) (4)

• Known as “fats”

EXAMPLES

• Oil

• Fats

• Waxes

• Steroid hormones

Main functions of lipids (6)

• Long-term kJ storage

  • Used when no more glucose

• Major component of cell membrane

• Carries fat-soluble compounds

  • Mainly vitamins

• Base for some hormone synthesis

  • Ex. E, T, aldosterone

• Body insulation

• Water proofing

  • Ex. Skin (oil), Leaves (wax)

What are the 3 types of lipids? (3)

• Triglycerides

• Phospholipids

• Steroids

Properties of lipids (2)

• NOT polymers

  • Can’t combine to make longer macromolecules

    • Unrepetitive

• Saturated or unsaturated

Saturated vs Unsaturated (2) (2)

SATURATED

• From animals

• C chain saturated with H⁺

UNSATURATED

• From plants

• C chain unsaturated with H⁺

  • From C=C

What are triglycerides? (5)

• Neutral fats

• Solids @ room temp = fats

• Liquids @ room temp = oils

• Found around muscle, in brain, + under skin

  • Insulation + kJ storage

• Made up of 4 monomers

  • 1 glycerol

  • 3 fatty acids

What are waxes made of? (1)

• Long chain fatty acid + long chain alcohol OR C rings

  • Allows waterproofing

    • Ex. Leaves, skin, feathers

What are steroids made of? (4)

• 4 interlocking C rings

• Long C chains attached

• Non-polar

• Different ring arrangement + attached functional groups

Why is cholesterol important? (5)

• Acts as buffer

• Keeps fluidity of cell membrane

• Precursor for hormones

• Helps metab work efficiently

  • Ex. Needed for vitamin D production

• Makes bile acids

  • Helps digest fat

  • Helps absorb important nutrients

What are phospholipids? (2)

• Glycerol + 2 Fatty acid chains + PO₄

  • Difference betw. triglyceride + phospholipids = PO₄

• Main component of cell membrane

Anatomy of Phospholipids (1) (2) (2)

• Amphipathic compound

  • Polar + Non-polar end

HEAD

• PO₄ end

• Polar → hydrophilic

  • Dissolves in H₂O

TAIL

• Fatty acid end

• Non-polar → hydrophobic

  • Dissolve in each other (“like dissolves like”)

What does soap do to phospholipids? (OKAY I NEED TO FIGURE OUT HOW THIS WORKS CUZ NOTES MAKE NO SENSE)

• Soap = amphipathic

  • Similar structure to phospholipids

• Soap molecs surround the oil (creates micelle)

  • POLAR outside

  • NP inside (with oil)

• Polar dissolves with H₂O and takes oil w/ it