DNA, Cells, Organelles, Transport, and Body Plan A and P test 1

A comprehensive set of vocabulary flashcards covering DNA, transcription/translation, organelles (membrane-bound and non-membrane-bound), cell transport, cell physiology, body planes, serous membranes, body cavities, and basic anatomy/ physiology concepts.

Role of DNA

Stores genetic information and directs cellular activities by guiding protein synthesis.

What percentage of DNA codes for genes

Only a small portion; about 1-2% of DNA consists of genes.

Start codon

AUG; signals initiation of translation and codes for methionine.

Stop codons

UAA, UAG, UGA; terminate translation and do not code for amino acids.

Transcription

DNA is copied into RNA (mRNA) in the nucleus; prepares for protein synthesis.

Translation

mRNA is decoded by ribosomes to synthesize a polypeptide (protein) in the cytoplasm.

Final product of transcription

mRNA transcript of the gene.

Final product of translation

Polypeptide chain (protein) produced from mRNA.

DNA base pairing rules

A pairs with T; C pairs with G.

RNA base pairing to DNA

A-U, T-A, C-G, G-C (RNA uses uracil instead of thymine).

Chromosomes

Condensed DNA-protein structures visible during cell division.

Chromatin

Looser DNA-protein complex present most of the cell cycle; allows gene expression.

Nucleus (organelle)

Membrane-bound organelle that houses DNA and controls cell activities.

Mitochondria

ATP production (cellular respiration); energy powerhouse of the cell.

Rough endoplasmic reticulum

ER with ribosomes; synthesizes and processes proteins.

Smooth endoplasmic reticulum

ER without ribosomes; lipid synthesis and detoxification.

Golgi apparatus

Modifies, sorts, and packages proteins for secretion or delivery.

Lysosome

Contains digestive enzymes that break down waste materials.

Peroxisome

Breaks down fatty acids; detoxification; contains enzymes like catalase.

Vesicle

Small membrane-bound sac for transport within or outside the cell.

Chloroplast

Site of photosynthesis in plants; contains chlorophyll.

Vacuole

Storage sac; large central vacuole in plants maintains turgor.

Ribosome (non-membrane bound)

Site of protein synthesis; not surrounded by a membrane.

Cytoskeleton

Filaments that give cell shape, support, and enable movement.

Centrosome/Centrioles

Organizes spindle fibers during cell division.

Proteasome

Degrades unwanted or damaged proteins.

Cilia

Short, numerous projections that move substances along cell surfaces.

Flagella

Long, whip-like projections used for cell locomotion.

Microvilli

Finger-like extensions that increase surface area for absorption.

Diffusion

Movement of particles from high to low concentration until equilibrium.

Facilitated diffusion

Passive transport via membrane proteins down a concentration gradient.

Osmosis

Diffusion of water across a semipermeable membrane toward higher solute concentration.

Active transport

Energy-requiring transport moving substances against their gradient.

Primary active transport

Direct use of ATP to move substances against their gradient (e.g., Na+/K+ pump).

Secondary active transport

Uses ion gradients created by primary transport to move other substances (co-transport or antiport).

Vesicular transport

Transport of substances via vesicles (endocytosis and exocytosis).

Isotonic solution

Solute concentration equal to cell interior; no net water movement.

Hypertonic solution

Higher solute outside than inside; water moves out; cell shrinks.

Hypotonic solution

Lower solute outside than inside; water moves in; cell swells.

Resting membrane potential (RMP)

Electrical potential difference across the plasma membrane when the cell is at rest.

Two ions important to RMP

Sodium (Na+) and Potassium (K+); gradients maintained by the Na+/K+ pump.

Sodium-potassium pump

Na+/K+-ATPase: pumps 3 Na+ out and 2 K+ in against gradients; uses ATP.

Passive transport processes

Movement across the membrane without energy: diffusion, facilitated diffusion, osmosis.

Active transport processes

Energy-requiring transport: primary, secondary, and vesicular transport.

Structural units of organisms from smallest to largest

Atoms → Molecules → Organelles → Cells → Tissues → Organs → Organ systems → Organism.

Metabolism

Sum of all chemical reactions in the body.

Catabolism

Breakdown of larger molecules into smaller ones; releases energy.

Anabolism

Building up of complex molecules from smaller ones; requires energy.

Anatomy vs Physiology

Anatomy studies structure; physiology studies function; both explain the same body part differently.

Directional terms (opposites)

Anterior vs Posterior; Superior vs Inferior; Medial vs Lateral; Proximal vs Distal; Superficial vs Deep.

Five planes of the body

Sagittal (left-right), Midsagittal/Median (equal left and right), Frontal/Coronal (anterior/posterior), Transverse/Horizontal (superior/inferior), Oblique (angled plane).

Serous membrane that lines body cavities

Parietal serosa lines the cavity walls.

Serous membrane that covers organs

Visceral serosa covers the organs within cavities.

Function and location of serous fluid

Lubricates membranes to reduce friction; located between parietal and visceral layers in serous cavities.

Body cavities (two large divisions)

Dorsal (cranial and spinal) and Ventral (thoracic and abdominopelvic).

Major organs in dorsal cavity parts

Cranial cavity: brain; Vertebral (spinal) cavity: spinal cord.

Major organs in ventral cavity parts

Thoracic cavity: heart and lungs (pleural and pericardial). Abdominopelvic cavity: digestive organs, liver, bladder, reproductive organs.

Body part terminology (memory aid)

Terms used to describe location and direction on the body; memorize via flashcards or mnemonics.