Biomolecules (Macromolecules)

Large molecules made up of atoms that sustain life.

Carbohydrates

Fuels brain

Proteins

Enables functions

Lipids (fats)

Forms membranes

Nucleic Acids

Part of DNA

All cell types can produce all four macromolecules (and you can get them from food).

Structure = Function

Think screwdriver vs. hammer.

Monomer

Building block of biomolecules.

Polymer

Repeating units of monomers.

Polymerization

Monomers (repeating units) are bonded in varying lengths (polymers).

Energy Release

Energy release is how many bonds could be broken between monomers; not the number of monomers themselves.

Bond Breaking

Endothermic.

Requires energy.

Bond Making

Exothermic.

Releases energy.

Think of it like compressed springs.

Fire breaks apart weak bonds in fuel and forms more stable bonds as CO₂ and others, releasing energy.

Energy Expenditure

Prolonged exercise - after 30min, your body shifts from carbs to fats.

Carbohydrates

Made of carbon-hydrogen-oxygen.

Not all carbs are digestible due to their rigid chains (sa. fiber).

Types of Carbs

Simple Carbs/Sugars

Quick energy release.

These are easily broken down.

Composed of one or two monomers.

Glucose, Sucrose

Complex Carbs/Sugars

Time-release energy.

These take some amount of time to break down.

Composed of many monomers.

Starch, Fiber

Structure

Monosaccharides

One monomer

Glucose

Disaccharides

Two monomers

Sucrose

Polysaccharides

Many monomers

Starch

Lipids

Body Fat

These are made of lipids.

Brown Fat

Generates body heat.

White Fat

Used for energy storage.

Beige Fat

White fat that acts like brown fat.

Other Types of Lipids

Steroids (Hormones)

Rigid ring structure, no tail, allows it to last longer in the bloodstream.

Phospholipids

Two tails - better for cell membranes.

Allows them to connect together and be semi-permeable.

Waxes

Strongly hydrophobic, one long fatty acid chain, no water-loving head.

Properties of Lipids

Mainly used for energy. They generally have more bonds than carbohydrates, so they function better for long-term energy storage. They take up less space b/c they don't attract water.

Non-polar, fats, insoluble in water. Have more energy due to many C-H bonds (carbon-hydrogen tail).

Glycerol

Hydrophilic head

Fatty Acids

Hydrophobic tail

Dietary Fats

Saturated Fats

Straight chains pack together tightly.

These are harder to break down and move along the bloodstream, so they can clog arteries and such.

Unsaturated Fats

Kinked chains cannot be tightly packed.

These are liquid at room temperature.

Triglycerides

Main lipid in our diet.

Three fatty-acid tails.

The head/tail combo (glycerol head + fatty acid tail) is one monomer.