Biology EOC Review

Polarity

Water is polar due to the unequal sharing of electrons between hydrogen and oxygen atoms.

Hydrogen Bonding

Bonds between water molecules, leading to surface tension.

Surface Tension

Caused by hydrogen bonds, allowing small creatures to walk on water.

Cohesion

Attraction between like molecules (e.g., water molecules sticking to each other).

Adhesion

Attraction between unlike molecules (e.g., water sticking to other substances).

Capillarity (Capillary Action)

Ability of water to move up thin tubes, aiding plants in water acquisition.

Ability to Moderate Temperature

Water's high heat capacity stabilizes air and water temperatures by absorbing/releasing heat.

Expands When Frozen

Water expands upon freezing due to hydrogen bonds, becoming less dense and floating, which insulates aquatic life.

Solvent of Life

Many substances (e.g., salt, sugar) dissolve in water.

Polymers

Large molecules made of repeating monomer units.

Carbohydrates

1:2:1 ratio of C, H, and O. Ringed structures.

Proteins

C, H, O, N, and sometimes S.

Nucleic Acids

C, H, O, N, P. Phosphate group, sugar, and a nitrogenous base.

Lipids

C, H, O (mostly C and H - fatty acids & glycerol). No monomers (not made of repeating units).

Glucose

Immediate energy source.

Polysaccharides

Starches; cell walls and structural support.

Proteins

Structure (cells, hair, nails, muscles, skin). Enzymes: speed up reactions. Transport, hormones, helps fight disease.

Enzymes

Catalysts that speed up reactions by lowering activation energy. Factors like concentration, pH, and temperature affect enzyme function. Enzymes exhibit specificity, fitting into substrates like a key into a lock. Enzymes work in optimal conditions.

Nucleic Acids

Store/transmit genetic information (DNA & RNA).

Lipids

Insulation, protection, energy storage, barriers (plasma membrane).

Homeostasis

Regulation of internal environment for survival.

pH

Measure of acidity (0 -

Stimulus

Anything causing a reaction in an organism.

Metabolism

All chemical reactions within an organism.

Scientific Theory

Well-supported explanation; the most powerful explanation scientists offer. Can be overturned.

Laws

Well-supported descriptions of relationships but don’t explain why.

Cell Theory

1. The cell is the basic unit of life. 2. All organisms are made of cells. 3. Cells come from preexisting cells.

Theory of Biogenesis

Life comes from life.

Theory of Spontaneous Generation

Life comes from non-living material (disproved by Frances Redi).

All cells have

Plasma membrane, ribosomes, cytoplasm, genetic material.

Chromosomes

Contain genetic material copied and passed on during reproduction.

Prokaryotic Cells

No membrane-bound organelles. Only in bacteria, unicellular.

Eukaryotic Cells

Have membrane-bound organelles (nucleus, lysosomes, mitochondria, Golgi apparatus, ER, vacuoles, chloroplasts). Fungi, protists, plants, animals; unicellular or multicellular.

Organelle

Membrane-bound structure with specific functions in eukaryotic cells.

Prokaryotic Structures

Cell wall, plasma membrane, cytoplasm, plasmid (circular DNA), ribosomes, flagella.

Eukaryotic Structures

Unicellular or multicellular

Cellular Organization

Cells, tissues, organs, organ systems, organisms (for multicellular organisms).

Cell Wall

Inflexible barrier; support & protection.

Plasma Membrane

Selectively permeable barrier.

Cytoplasm

Everything inside the plasma membrane.

Nucleus

Control center containing DNA.

Nuclear Envelope

Membrane enclosing the nucleus.

Nucleolus

Makes ribosomes, found in the nucleus.

Chromatin

Relaxed form of DNA.

Ribosomes

Help make proteins.

Endoplasmic Reticulum

Site of protein synthesis.

Microtubules/Filaments

Cytoskeleton, involved in movement & shape of cell.

Vacuoles

Storage.

Mitochondria

Powerhouse, cellular respiration occurs here, makes energy (ATP).

Chloroplasts

Made of thylakoids, & chlorophyll pigments, does photosynthesis

Golgi Apparatus

Packs & sends proteins.

Lysosomes

Breaks down old/harmful substances.

Cilia

Hair-like structures for movement & feeding.

Flagella

Whip-like tail for movement.

Plasma Membrane

Selective barrier made of proteins and phospholipids.

Diffusion

Movement from high to low concentration.

Hypotonic

Cell swells.

Hypertonic

Cell shrinks.

Isotonic

Cell stays the same.

Osmosis

Movement of water across a membrane from high to low concentration.

Passive Transport

No energy required, moves with the concentration gradient; includes facilitated diffusion, carrier proteins, and ion channels.

Active Transport

Requires energy, moves against the concentration gradient; includes sodium-potassium (Na-K) pump.

Photosynthesis

Organisms use sunlight to make glucose.

1st Stage (Light Dependent)

Sun's energy converted into chemical energy (ATP).

2nd Stage (Light Independent/Calvin Cycle)

ATP fuels glucose production.

Cellular Respiration

Occurs in mitochondria; oxygen & glucose produce energy (ATP).

Photosynthetic Organisms

Plants, algae, seaweed, plankton, photosynthetic bacteria.

Roots

Absorb water & anchor plant.

Stems

Support leaves/flowers.

Leaves

Photosynthesis (stoma/stomata, chloroplasts, chlorophyll).

Flowers

Reproductive parts (stamen, pistil).

Fruits

From ovaries containing eggs which become seeds (plant embryo), and cones.

Physiological Processes

Photosynthesis, cellular respiration, transpiration, reproduction.

Meristematic

Region of growth.

Ground

Makes up most of the plant.

Dermal

Epidermis or outer covering of plant.

Vascular

Xylem (transports water & minerals up), phloem (transports sugar throughout plant).

Cambium (cork or vascular cambium)

Meristematic tissue producing new transport cells; cork is outer bark.

Guard Cells

Surround the stoma/stomata (pore), regulate opening & closing based on water availability.

Stoma/Stomata

Pore for gas exchange (CO2 & O2) and water.

DNA Replication

Copying DNA using A-T-C-G; accuracy is essential.

Protein Synthesis (Gene Expression)

Making proteins from DNA in 2 steps: 1. Transcription: m-RNA copies info from DNA using AUCG (occurs in the nucleus). 2. Translation: m-RNA brings codon to cytoplasm, t-RNA transfers correct amino acid to ribosome, r-RNA ensures correct order.

Codon

Three-base code sequence in m-RNA that specifies an amino acid.

Chromatin

Relaxed form of DNA.

Sister Chromatids

Two halves of a doubled chromosome.

Centromere

Holds sister chromatids together.

Spindle Fibers

Attach to centrioles, pull apart sister chromatids during anaphase.

Centrioles

Animal organelle, involved in cell division.

Haploid

1(n), one set of chromosomes.

Diploid

2(n), two sets of chromosomes.

Interphase

Preparation & growth, chromosomes doubled (as chromatin).

Prophase

DNA visible, nuclear envelope disappears, centrioles move.

Metaphase

Chromosomes in the middle.

Anaphase

Sister chromatids move apart.

Telophase

Nuclear envelope reappears, cell pinches in (animals) or forms cell plate (plants).

Cytokinesis

Division of cytoplasm.

Purpose of Mitosis

Repair, growth, development, asexual reproduction.

Homozygous

2 of the same alleles (TT or tt).

Heterozygous

2 different alleles (Tt).

Dominant

Trait that is observed.