AP Bio Exam

What are carbohydrates composed of?

Carbon, Hydrogen, Oxygen

What is the monomer of carbohydrates?

Monosaccharide

Examples of carbohydrates

Glucose, Fructose, and Galactose

Disaccharides

Two monosaccharides

What bond holds disachharides together?

Glycosidic linkage

Name the structural carbohydrates

Cellulose and Chitin

Where is cellulose found?

Plant cell walls

Where is Chitin found?

Fungi cell walls and exoskeleton of arthopods

Name the storage carbohydrates

Starch and glycogen

Where is starch found?

Plants

Where is glycogen found?

Animals

What are nucleic acids composed of?

Carbon, Hydrogen, Oxygen, Nitrogen, and phosphorous

What is the monomer of nucleic acids?

Nucleotide

What bond holds disachharides together?

Phosphodiester linkage (between phosphate and hydroxyl)

DNA nitrogenous bases

A, T, C, G

DNA sugar

deoxyribose

DNA strandedness

double

RNA nitrogenous bases

A, U, C, G

RNA sugar

ribose

RNA strandedness

double

Purines

• Double ring

• A & G

Pyrimidine

• Single Ring

• C, U, T

How many hydrogen bonds are between A & T?

2

How many hydrogen bonds are between C & G?

3

What are proteins composed of?

Carbon, Hydrogen, Oxygen, Nitrogen, & Sulfur

Monomer of protein

Amino acid

What bond holds amino acids together?

a peptide bond (between carboxyl and amino groups)

How do R group properties affect protein folding?

• Hydrophilic R groups: Located on the exterior (interact with water).

• Hydrophobic R groups: Buried in the interior (avoid water).

• Charged R groups: Typically on the exterior (form ionic bonds).

What bonds are in between amino acids of the primary level of protein structures?

Peptide bonds

What is the structure of the primary level of a protein structure?

A string of amino acids

What bonds are present in the secondary level of a protein structure?

Hydrogen bonds between backbone

What is the structure of the secondary level of a protein structure?

Alpha helix or beta pleated sheet

What bonds are present in the tertiary level of a protein structure?

ANY (hydrogen, covalent, ionic, …) between R groups

What is the structure of the tertiary level of a protein structure?

Final 3D structure

What bonds are present in the quaternary level of a protein structure?

ANY (hydrogen, covalent, ionic, …) between R groups of different polypeptides

What are lipids composed of?

Carbon, hydrogen, oxygen, and phosphorus (in phospholipids)

Are lipids polar or nonpolar?

nonpolar

What are phospholipids composed of

a hydrophilic head that’s attracted to water and a hydrophobic tail that’s repelled by water

Where are polar covalent bonds between oxygen and hydrogen located?

In the water molecule

Where are hydrogen bonds between oxygen and hydrogen located?

Between water molecules

Cohesions

Water molecules attracted to other water molecules

Adhesion

Water molecules attracted to other polar substances

What does partial negative oxygen bind with?

other polar molecules (partial negative end) and positively charged ions (cations)

What does partial positive hydrogen bind with?

Other polar molecules (partial negative end) & negatively charged ions (anions)

Surface tension

Cohesion develops a “surface” based on the interaction of hydrogen bonds

What is the relationship between concentration of hydronium/hydrogen ion and pH?

As the concentration of hydronium/hydrogen ion increases, the pH decreases

Describe the atoms and typed of bonds in a glucose molecule

The atoms are carbon, hydrogen, and oxygen and are held together by covalent bonds

The double-strand breaks occur along the DNA backbone. Describe the process by which the breaks occur.

Covalent bonds between the sugars and phosphates/nucleotides are broken

Structure of nucleus

Double membrane (nuclear envelope) with pores

Functions of nucleus

• Stores genetic information (DNA)

• Synthesis of RNA

• Ribosome subunit assembly

Structure of Rough ER

Membrane studded with ribosomes attached to nuclear envelope

Functions of rough ER

• Site of membrane-bound protein and secreted protein synthesis

• Cell compartmentalization

• Mechanical support

• Role in intracellular transport

Structure of smooth ER

Folded and tubelike

Functions of smooth ER

• Detoxification

• Calcium storage

• lipid synthesis

Mitochondria structure

Double membrane (outer: smooth; inner: highly folded)

Functions of mitochondria

• Site of oxidative phosphorylation (Cristae/inner membrane)

• Site of Krebs cycle (matrix)

Chloroplast structure

Double outer membrane

Functions of chloroplast

• Site of photosynthesis

• Thylakoid: Light reactions

• Stroma: Calvin-Benson cycle

Golgi complex structure

Membrane-bound structure composed on flattened sacs

Functions of Golgi complex

• Folding and chemical modification of synthesized proteins

• packaging protein traffic

Ribosome structure

• Composed of rRNA and protein

• large and small subunits

• types: bound or free (cytoplasm)

Ribosome function

Protein synthesis

Vacuole structure

Membrane-bound sac

Vacuole functions

• Storage and release of macromolecules and cellular waste products

• Control water retention - turgor pressure

• Contractile: osmoregulation (protist)

• Food: phagocytosis, fuse with lysosome

Lysosome structure

membrane-enclosed sacs that contain hydrolytic enzymes

Lysosome function

Intracellular digestion (recycle cell organic materials and programmed cell death: apoptosis)

Hypertonic solution

• High solute concentration

• Low free water concentration

• Gains water from hypotonic solution

Isotonic solution

• Equal solute concentration (as other solution)

• Equal free water concentration (as other solution)

• Equal water movement in and out of solution

Hypotonic solution

• Low solute concentration

• High free water concentration

• Loses water to hypertonic solution

Simple diffusion

• Passive transport

• Down concentration gradient

• Small, nonpolar

• No transport protein needed

• Examples: CO₂, O₂, N₂, steroids

• Small amount of H₂O leak through membrane

Facilitated diffusion

• Passive transport

• Down concentration gradient

• Small molecules

• Requires transport protein

• Example: water, Na⁺, K⁺, Ca⁺

Active Transport

• Requires input of NRG

• Against concentration gradient

• Requires transport protein (carrier protein)

• Example: Na⁺, K⁺, Ca⁺, H⁺

What are plasma membranes composed of?

Phospholipids, membrane proteins, glycolipids/glycoproteins, and cholesterol

Endocytosis

Import of materials

Exocytosis

• Export of materials

• Rough ER (synthesize) —> Golgi complex (package/modification) —> plasma membrane

Are endergonic reactions spontaneous?

No

Do endergonic reactions absorb or release energy?

absorb

Are exergonic reactions spontaneous?

Yes

Do exergonic reactions absorb or release energy?

release

Functions of enzymes

• Biological catalyst

• Speeds up chemical reactions

• Reduces the activation energy

Are enzymes proteins?

Yes

Steps of enzyme-substrate binding

1. Substrate enters active site of enzyme

2. Enzyme/substrate complex forms

3. Substrate is converted to products

4. Products leave the active site of the enzyme

What do competitive inhibitors bind to?

The active site

What do non competitive inhibitors bind to?

The allosteric site

Where does glycolysis occur?

Cytosol

Starting material of glycolysis

Glucose

Products of glycolysis

• 2 pyruvate

• 2 NADH

• 2 ATP

Where does oxidative phosphorylation occur?

Mitochondrial cristae

Starting material of oxidative phosphorylation

NADH/FADH2

Products of oxidative phosphorylation

ATPs

What are the two parts of oxidative phosphorylation

Electron transport chain & chemiosmosis

Election transport chain in cellular respiration

• Protons pumped into intermolecular space

• Generates proton gradient

• Final electron acceptor: oxygen

Chemiosmosis

• ATP synthase uses proton gradient

• Synthesizes ATP

Where does the krebs cycle occur?

Mitochondrial matrix

What is the starting material of the Krebs cycle?

Acetyl CoA

Products of Krebs cycle

• 2 CO2

• 3 NADH

• 1 FADH2

• 1 ATP

Where does photosynthesis occur?

Thylakoid membrane

Starting materials of photosynthesis

• Water (electrons)

• Photons (energy)

Products of photosynthesis

• ATP

• NAD

Linear electron flow

• Photosystem 1 & 2

• Synthesizes ATP & NADPH