TEAS Science

Cell Membrane

Semi-permeable barrier regulating what enters and exits the cell.

Nucleus

Control center of the cell containing DNA.

Mitochondria

Produces ATP; powerhouse of the cell.

Ribosomes

Site of protein synthesis.

Golgi Apparatus

Packages and ships proteins.

Endoplasmic Reticulum

Transport network; smooth = lipids, rough = proteins.

Diffusion

Movement of molecules from high to low concentration.

Osmosis

Diffusion of water across a membrane.

Active Transport

Movement using ATP from low to high concentration.

Mitosis

Cell division creating two identical daughter cells.

Meiosis

Cell division creating gametes with half the chromosomes.

Epithelial Tissue

Covers surfaces and lines organs.

Connective Tissue

Supports, binds, and protects; includes blood and bone.

Muscle Tissue

Skeletal, cardiac, or smooth muscle for movement.

Nervous Tissue

Transmits electrical impulses.

Skeletal System Functions

Support, protect organs, movement, mineral storage, blood cell formation.

Osteoblasts

Build bone.

Osteoclasts

Break down bone.

Compact Bone

Dense outer bone layer.

Spongy Bone

Inner bone with red marrow for blood formation.

Muscular System Types

Skeletal, cardiac, smooth muscle.

Sliding Filament Theory

Actin and myosin slide to contract muscle.

Role of Calcium in Muscles

Allows myosin to bind to actin.

ATP in Muscle Contraction

Provides energy for contraction and relaxation.

Cardiovascular System Function

Transport oxygen, nutrients, hormones, waste.

Heart Chambers

Right/Left atria; Right/Left ventricles.

Blood Flow Order

Body → RA → RV → Lungs → LA → LV → Body.

Arteries

Carry blood away from the heart.

Veins

Carry blood toward the heart.

Capillaries

Gas and nutrient exchange.

Systole

Heart contraction.

Diastole

Heart relaxation.

Blood Pressure

Force of blood on vessel walls; normal 120/80.

Cardiac Output

Stroke Volume × Heart Rate.

Respiratory System Function

Gas exchange supplying oxygen and removing CO₂.

Inhalation

Diaphragm contracts downward.

Exhalation

Diaphragm relaxes upward.

Alveoli

Site of gas exchange.

Oxygen Transport

O₂ binds hemoglobin in red blood cells.

CO₂ Transport

Carried as bicarbonate in blood.

Digestive System Function

Breakdown and absorption of nutrients.

Peristalsis

Wave-like contractions moving food.

Enzymes

Pancreatic amylase, lipase, protease.

Small Intestine

Main site of absorption.

Large Intestine

Water absorption and waste formation.

Urinary System Function

Removes waste; maintains fluid & electrolyte balance.

Nephron Functional Flow

Bowman's capsule → PCT → Loop of Henle → DCT → Collecting duct.

Filtration

Occurs in glomerulus.

Reabsorption

Movement of needed substances back to blood.

Secretion

Movement of waste into filtrate.

ADH

Increases water reabsorption.

Endocrine System Function

Hormone communication regulating body processes.

Insulin

Lowers blood glucose.

Glucagon

Raises blood glucose.

Thyroid Hormones

Regulate metabolism.

Negative Feedback

Body maintains homeostasis by reversing changes.

Nervous System Function

Rapid communication via electrical signals.

Neuron

Basic nerve cell that transmits impulses.

Action Potential

Electrical signal triggered by sodium influx.

Synapse

Junction where neurotransmitters transmit signals.

Central Nervous System

Brain and spinal cord.

Peripheral Nervous System

All nerves outside CNS.

Immune System Function

Defend body from pathogens.

Innate Immunity

Fast, non-specific defense.

Adaptive Immunity

Specific, slower response with memory.

Antibodies

Proteins made by B-cells to target antigens.

Macrophages

Engulf pathogens.

T-cells

Attack infected cells directly.

Chemistry: Proton

Positive charge; found in nucleus.

Chemistry: Neutron

Neutral charge; found in nucleus.

Chemistry: Electron

Negative charge; orbits nucleus.

Ionic Bond

Electron transfer forming charged ions.

Covalent Bond

Shared electrons between atoms.

Hydrogen Bond

Weak attraction between molecules.

pH Scale

0–6 acid, 7 neutral, 8–14 base.

Genetics: DNA

Double-stranded molecule storing genetic info.

Genetics: RNA

Single-stranded; helps make proteins.

Transcription

DNA → mRNA.

Translation

mRNA → Protein.

Codon

Three-base sequence coding for amino acid.

Allele

Variant form of a gene.

Scientific Method Steps

Question → Hypothesis → Experiment → Analysis → Conclusion.

Independent Variable

What is changed in the experiment.

Dependent Variable

What is measured.

Control Group

Group without treatment for comparison.