bio final

What are the steps of the scientific method (in order)?

Observation → Curiosity → Question → Hypothesis → Experiment → Data/Observations → Results → Analysis → Conclusion → Theory

What is a hypothesis?

A testable, falsifiable explanation for an observation

What is a theory?

A well-supported explanation backed by repeated experiments and evidence

qualitative data

descriptive

quantitative data

numerical with units

What is a positive control?

Shows expected results to confirm experiment works

What is a negative control?

Shows no effect to ensure results aren’t due to outside factors

What are the characteristics of life?

Made of cells, metabolism, homeostasis, grow & develop, reproduce, respond to stimuli, evolve

Are viruses living?

No—lack cells and metabolism, require host

What defines a prokaryotic cell?

No nucleus, small, simple, DNA in cytoplasm (bacteria)

What defines a eukaryotic cell?

Nucleus, membrane-bound organelles, larger, complex

What structures do all cells have?

DNA, ribosomes, cytoplasm, cell membrane

What is the cell membrane made of?

Phospholipid bilayer with embedded proteins

Why is the membrane selectively permeable?

Controls what enters and leaves the cell

What is diffusion?

Movement from high → low concentration (no energy)

What is facilitated diffusion?

Diffusion using transport proteins (no energy)

What is osmosis?

Diffusion of water across a semipermeable membrane

Define isotonic, hypertonic, hypotonic

• Isotonic: equal solute → no net change

• Hypertonic: more solute outside → cell shrinks

• Hypotonic: less solute outside → cell swells/lyses

What is active transport?

Movement from low → high concentration using ATP

Endocytosis vs exocytosis?

Endocytosis = bring in; Exocytosis = release out

What do enzymes do?

Speed up chemical reactions

How do enzymes work?

Lower activation energy

What affects enzyme activity?

Temperature, pH, substrate concentration

What happens if enzymes denature?

Shape changes → enzyme stops working

Difference between inhibitors & activators?

Inhibitors slow/stop enzymes; activators increase efficiency

What elements make up most macromolecules?

CNSHOP (carbon, nitriogen, sulfur, hydrogen, oxygen, phospurase)

Monomer of carbohydrates?

Monosaccharides (glucose)

Function of carbohydrates?

Quick energy, structure, cell communication. Examples: Starch, glycogen, cellulose

Lipid building blocks?

Glycerol + fatty acids

Functions of lipids?

Long-term energy, membranes, hormones, insulation. Examples: Fats, oils, steroids, phospholipids

Monomer of proteins?

Amino acids (20 types)

Functions of proteins?

Enzymes, structure, transport, movement, defense. Examples: Enzymes, hemoglobin, collagen

Monomer of nucleic acids?

Nucleotides (A, T, C, G, U)

Function?

Store & transmit genetic information. Examples: DNA, RNA

Function of the nucleus?

Stores DNA; controls cell activities

Function of ribosomes?

Protein synthesis

RER vs SER?

RER: proteins; SER: lipids & detox

Golgi apparatus function?

Modifies, sorts, packages proteins

Mitochondria function?

Cellular respiration; ATP production

Lysosome function?

Digestion & recycling

Vacuole function?

Storage; maintains turgor pressure (plants)

Chloroplast function?

Photosynthesis (plants only)

Why do cells divide instead of growing large?

High surface area-to-volume ratio = efficient transport

What happens if cells get too large?

Nutrient & waste exchange slows

What is ATP?

Cell’s main energy molecule

What is homeostasis?

Maintaining stable internal conditions

What is the fluid mosaic model?

Membrane is flexible with moving proteins

What are cytoskeleton functions?

Shape, movement, transport within cell