BIO100 Lecture #2 Nutrition

Why is carbon special in life?

It can form many shapes like long and branching chains. These chains are the skeletons for a wide variety of atoms.

Functional Groups

Sets of atoms attached to the C skeleton. Play important roles in reactions with other compounds.

Hydroxyl group

OH

Amino Group

(—NH2) a functional group composed of nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton. Can act as a base in solution, accepting a hydrogen ion and acquiring a charge of +1.

Carboxylic Acid

COOH

Macromolcules

Large molecules with a complex structure. Most organic molecules.

- mostly polymers

4 Classes of Organic Molecules

Carbs (bread & candy), proteins (meat & soy), lipids (butter & oil), nucleic acids (everything except processed food)

Lipids

Fats and oils

- mostly consume triglyceride.

- hydrophobic (do not mix with water)

Uses of Lipids

- long-term energy storage

- cushion

- insulation

- membrane function

- hormonal regulation

Triglycerides

Typical dietary fats. The C/H chains in the fatty acids store energy

How do cell membranes depend on lipids?

Cell membrane isolate lipids from water by regulating the passage of material into the cell. There are simply 2 stacked layers of phospholipids.

Saturated, Unsaturated Cis Fat, Unsaturated trans Fat

saturated= saturated with hydrogen, solid

unsaturated= one or more double bonds with one fewer hydrogen on each double bond, mostly cis double bonds, liquid

Saturated Fats

- Contain max number of H

- Solid at room temp.

- Higher amounts in animal products

- All C-C single bonds

- Straight F.A chains

- Less healthful.

Unsaturated Fat

- less than max number of H

- liquid at room temp

- higher amounts in plant products

- some C=C bonds in F.A. chains

- bends in fatty acid chains.

- healthfuler

Healthful Lipids

Some lipids are essential to a heathy diet

- Fats containing w-3 fatty acids reduce risk of heart disease.

- Foods rich in essential fats are part of a balanced diet.

Cholesterol

A lipid that maintains fluidity in animal cell membranes.

- not a Triglyceride

- steroid hormone synthesis

- produced by the organism or obtained from food.

- transported by lipoproteins

Lipids and Heart-vascular diease

Excess cholesterol may be stored into the arteries and build up plaque. This can cause fat to rupture into the bloodstream or cause a heart attack.

What does high cholesterol mean?

LDL "Bad" = can be increased through poor diet

HDL "Good" - can be increased through exercise

NOT DIFFERENT KINDS OF CHOLESTEROL

What are some tasks proteins perform?

Defense (antibodies), Structure (keratin), enzymes, movement (muscle contraction)

Proteins

Polymers of amino-acids. Function and structure is determined by a precise amino-acid sequence.

Polypeptide

A chain of amino acids. Twists and folds to form a unique 3-D shape. Chains may be joined together into a large complex.

How do you recognize an animo acid?

Transmembrane Proteins

Three ion pumps highly specific to an ion. A protein can bind at the ion binding site and block the bump, like venom.

Apamin

Bee venom. Smallest proteic venom.

9 Essential Amino-acids

Valine, leucine, isleucine, methione, trytophan, phenlatimine, threoine, lysine, hisitidine.

- essential because we cannot make them

Dehydration Synthesis Reaction

Dense Irregular