Learn: AP BIO

Why is water polar?

Oxygen pulls electrons harder than hydrogen, so O is slightly negative and H is slightly positive.

Bond inside water

Polar covalent.

Bond between water molecules

Hydrogen bond.

Cohesion

Water sticks to water.

Adhesion

Water sticks to other surfaces.

Why does water have high specific heat?

Hydrogen bonds take energy to break, so water heats slowly.

Why does sweating cool you?

Evaporation uses heat from your body.

Why does ice float?

Frozen water spreads out, making ice less dense.

Hydrophilic

Likes water.

Hydrophobic

Avoids water.

Dehydration synthesis

Builds bigger molecules and releases water.

Hydrolysis

Breaks bigger molecules and uses water.

Easy memory

Dehydration builds; hydrolysis breaks.

Monomer (Carbohydrates)

Monosaccharide.

Polymer (Carbohydrates)

Polysaccharide.

Bond (Carbohydrates)

Glycosidic bond.

Main job (Carbohydrates)

Quick energy and energy storage.

Starch

Plant energy storage.

Glycogen

Animal energy storage.

Cellulose

Plant cell walls.

How to identify a carbohydrate picture

Ring shape with lots of -OH groups.

Main job (Lipids)

Long-term energy, membranes, signaling.

Fatty acid

Long carbon-hydrogen chain with COOH at the end.

Saturated fat

No C=C double bond; straight.

Unsaturated fat

Has C=C double bond; kinked.

Triglyceride

Glycerol + 3 fatty acids.

Phospholipid

Head + 2 fatty-acid tails.

Phospholipid head

Hydrophilic.

Phospholipid tails

Hydrophobic.

Steroid

4 connected rings.

How to identify triglyceride

3 tails.

How to identify phospholipid

Head + 2 tails.

How to identify steroid

4 rings.

Monomer (Proteins)

Amino acid.

Polymer (Proteins)

Polypeptide.

Bond (Proteins)

Peptide bond.

How to identify an amino acid

Central C with NH₂, COOH, H, and R.

R group

Part that changes between amino acids.

Primary structure

Amino acid sequence.

Secondary structure

Alpha helix or beta sheet.

Tertiary structure

Overall 3D shape of one protein chain.

Quaternary structure

Multiple protein chains together.

What holds secondary structure?

Hydrogen bonds.

What affects tertiary structure?

R-group interactions.

Hydrophilic R groups

Usually face outward toward water.

Hydrophobic R groups

Usually fold inward.

Denaturation

Protein loses shape and function.

Monomer (Nucleic Acids)

Nucleotide.

Polymers (Nucleic Acids)

DNA and RNA.

Nucleotide parts

Phosphate + sugar + base.

DNA sugar

Deoxyribose.

RNA sugar

Ribose.

DNA bases

A, T, C, G.

RNA bases

A, U, C, G.

Purines

A and G; 2 rings.

Pyrimidines

C, T, U; 1 ring.

A-T bonds

2 hydrogen bonds.

C-G bonds

3 hydrogen bonds.

How to identify a nucleotide

Phosphate + sugar + base.

How to identify a purine

2 rings.

How to identify a pyrimidine

1 ring.

GC means

Guanine-cytosine.

Why is GC stronger than AT?

GC has 3 hydrogen bonds; AT has 2.

More GC means

Higher melting temperature.

Hydroxyl

-OH.

Amino

-NH₂.

Carboxyl

-COOH.

Methyl

-CH₃.

Sulfhydryl

-SH.

Carbonyl

C=O.

Phosphate

P surrounded by O atoms.

Independent variable

What you change.

Dependent variable

What you measure.

Control group

Comparison group.

Mean

Average.

Median

Middle number.

Which is less affected by outliers?

Median.

Standard deviation

How spread out the data are.

Null hypothesis

No significant difference.

Chi-square

Compares observed vs expected results.

Chi-square uses

Raw counts.

χ² > critical value

Reject the null hypothesis.

Ring + lots of OH

Carbohydrate.

Long C-H chain + COOH

Fatty acid.

Straight fat chain

Saturated.

Kinked fat chain / C=C

Unsaturated.

3 tails

Triglyceride.

Head + 2 tails

Phospholipid.

4 connected rings

Steroid.

NH₂ + C + COOH + R

Amino acid.

Phosphate + sugar + base

Nucleotide.

2-ring base

Purine.

1-ring base

Pyrimidine.

Spiral protein shape

Alpha helix.

Folded sheet protein shape

Beta sheet.