BIO 110 - Recitation Quiz #2: Key Concepts on Macromolecules and pH Scales

Macromolecules

molecule composed of polymers.

-each MM has monomer, bonds that link them together, & their functions.

polymers

large molecules composed of multiple monomers

categories of macromolecules are defined by

monomers

Synthesis vs. Degradation

synthesis: builds macromolecules

degradation: breaks macromolecules down

condensation reactions

link monomers together (covalent bonds) to form a polymer (MM)

- water is a product of this reaction

hydrolysis reactions (water lysis)

water is used as a reactant to break macromolecules back into their individual monomers.

carbohydrates

MM with chemical formula (CH2O)n

-H & O ratio similar to water

-monomers are simple sugars

monosaccharides

simple sugars: glucose, fructose, galactose

polysaccharides

polymers of monosaccharides: cellulose, starch, glycogen

cellulose

a polymer of beta glucose monomers held together by beta linkages.

importance of cellulose

-provides shape & rigidity to plant cells

-important to humans (wood, heat, tools, etc.)

-not digestible

beta form of glucose formation

cellulose cable; 1 strand of cellulose; monomer of cellulose

Water = polar molecule

-Water held together by 2 covalent bonds

-Oxygen is much more electronegative than hydrogen (polar covalent bonds)

-Causes partial charges (water is polar)

hydrogen bonds

-attraction between a partially +H (polar covalent bond) & another atom with partially - atom

-need hydrogen donor & acceptor (partially - atom)

-1 H2O molecule can form 4 hydrogen bonds

Methane molecules

can't from hydrogen bonds; is a gas at room temp

hydrophilic

"water loving"

-polar molecules are soluble in water

hydrophobic

"water fearing" & antipathic

-nonpolar molecules are insoluble in water

Acid

donates protons (H+)

Base

accepts protons (H+)

High pH

OH- (base)

Low pH

H+ (acid_)

Independent variable (Lab 2)

pH

Dependent variable (Lab 2)

electrical charge of proteins

Proteins used in Lab 2

-Serum Albumen (blue)

-Cytochrome C (orange)

-Myoglobin (brown)

amino acids

monomers that build a protein

Alpha carbon

the central carbon atom of each amino acid (4 bones)

Amino acid structure

R group

this is what differs amino acids.

-ionic, polar, or non-polar

-ionic matters for electrophoresis

pH

the negative logarithm of the hydrogen ion concentration

- (mol/L) (-log[H+])

-1 unit change in pH = 10 fold change in H+ concentration

pH scale

0 (acidic) to 7 (neutral) to 14 (basic)

Neutral pH

[H+] = [OH-]

- Isoelectric point: where an individual molecule has no net charge (could theoretically be any pH)

Acidic pH

[H+] > [OH-]

Basic pH

[H+] < [OH-]

Proteins

polymers of amino acids linked by peptide bonds

amino acids with ionic R groups

aspartic acid, glutamic acid, lysine, arginine, and histidine

How do proteins become charged?

- Amino groups gain at low pH (H+ , attracted to - pole)

- Carboxyl group lose at high pH (OH- , attracted to + pole)