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Three parts of cell theory

All living things are made of cells; cells are the basic unit of life; cells come from preexisting cells.

Atomic number

Number of protons in an atom.

Mass number

Sum of protons and neutrons in an atom.

Weakest bond in biology

Hydrogen bond.

Why is water polar?

Oxygen is more electronegative than hydrogen.

What does pH measure?

Hydrogen ion (H⁺) concentration.

How much more acidic is pH 3 than pH 5?

100 times.

Four macromolecules

Carbohydrates, lipids, proteins, nucleic acids.

Monomer of carbohydrates

Monosaccharides.

Monomer of proteins

Amino acids.

Monomer of nucleic acids

Nucleotides.

Reaction that builds polymers

Dehydration synthesis.

Reaction that breaks polymers

Hydrolysis.

What are enzymes?

Proteins that speed up chemical reactions.

What do enzymes lower?

Activation energy.

What happens when an enzyme denatures?

Loses shape and function.

What does a competitive inhibitor do?

Competes for the active site.

How does substrate concentration affect enzyme rate?

Rate increases until saturation.

Difference between prokaryotes and eukaryotes

Eukaryotes have a nucleus and membrane-bound organelles.

Function of ribosomes

Protein synthesis.

Function of Rough ER

Protein synthesis for secretion.

Function of Smooth ER

Lipid synthesis and detoxification.

Function of Golgi apparatus

Modifies, sorts, and ships proteins.

Function of lysosome

Digestion and recycling.

Function of peroxisome

Detoxification and oxidation.

Function of mitochondria

ATP production (cellular respiration).

What is the fluid mosaic model?

Phospholipid bilayer with embedded proteins.

What is selective permeability?

Only certain substances can cross the membrane.

Simple diffusion definition

Down gradient, no protein, no ATP.

Facilitated diffusion definition

Down gradient with transport protein.

Active transport definition

Against gradient using ATP.

Osmosis definition

Diffusion of water.

Effect of hypertonic solution on cell

Cell shrinks.

Effect of hypotonic solution on cell

Cell swells.

What crosses membranes easily?

Small nonpolar molecules (O₂, CO₂).

Overall equation of cellular respiration

Glucose + O₂ → CO₂ + H₂O + ATP.

Where does glycolysis occur?

In the cytosol.

Where does the Krebs cycle occur?

In the mitochondrial matrix.

Where does electron transport chain (ETC) occur?

In the inner mitochondrial membrane.

Final electron acceptor in respiration

Oxygen.

What does ATP synthase use?

Proton (H⁺) gradient.

Overall equation of photosynthesis

CO₂ + H₂O + light → glucose + O₂.

Where do light reactions occur?

At the thylakoid membrane.

Where does the Calvin cycle occur?

In the stroma.

Which photosystem comes first?

Photosystem II.

What is oxidized in photosynthesis?

Water.

What is reduced in photosynthesis?

Carbon dioxide.

Function of helicase

Unzips DNA.

Function of primase

Adds RNA primers.

Function of DNA polymerase

Builds new DNA strand.

Function of ligase

Seals Okazaki fragments.

Function of mRNA

Carries genetic message.

Function of tRNA

Transfers amino acids.

Function of rRNA

Makes up ribosome.

Silent mutation

No amino acid change.

Missense mutation

One amino acid change.

Nonsense mutation

Creates premature stop codon.

Frameshift mutation

Insertion/deletion not in multiples of three.

What happens in G₁ phase?

Cell growth.

What happens in S phase?

DNA replication.

What happens in G₂ phase?

Preparation for mitosis.

What happens in prophase?

Chromosomes condense.

What happens in metaphase?

Chromosomes line up at the equator.

What happens in anaphase?

Sister chromatids separate.

What happens in telophase?

Two nuclei form.

What is cytokinesis?

Division of the cytoplasm.

When does crossing-over occur?

In prophase I.

What separates in anaphase I?

Homologous chromosomes.

Purpose of meiosis

To produce gametes.

Genotype definition

Genetic makeup of an organism.

Phenotype definition

Observable traits of an organism.

Why are males more affected by X-linked traits?

Males have only one X chromosome.

What does natural selection act on?

Phenotype.

What is genetic drift?

Random change in allele frequencies.

Drift strongest in which populations?

Small, isolated populations.

What is gene flow?

Movement of alleles between populations.

Hardy–Weinberg conditions

Large population, random mating, no mutation, no migration, no selection.

Formula for heterozygotes in Hardy-Weinberg

2pq.

Function of tumor-suppressor genes

Stop the cell cycle (act as brakes).

Function of oncogenes

Promote cell division (act as gas).