Flashcards Cell Biology: Organelles, Transport, Homeostasis & Feedback, Cell Structure and Function Vocab

Nucleolus

Structure inside the nucleus that makes ribosomes.

Chromatin

Made of DNA, located inside the nucleus.

Ribosomes

Organelles found on the Rough ER that synthesize proteins (e.g., insulin).

Mitochondria

Organelles that generate chemical energy in the form of ATP.

Golgi Body

Organelle that packages and creates vesicles used for transport/export.

Lysosomes

Organelles containing digestive enzymes responsible for breaking down substances inside the cell.

Chloroplast

Plant cell organelle responsible for photosynthesis (converting sunlight into chemical energy).

Vacuole

Organelle used to store cellular materials and manage waste.

Cell Wall & Chloroplasts

Two structures found in plant cells but absent in animal cells.

Plant vs. Animal Cell Shape

Plant cells have a fixed rectangular/cube shape, while animal cells have a flexible, round, or irregular shape.

Cell Membrane

Semipermeable phospholipid bilayer that regulates the flow of materials into and out of the cell to maintain homeostasis.

Passive Transport

Movement of substances across the membrane from high to low concentration that DOES NOT require energy.

Active Transport

Movement of particles from low to high concentration (against gradient) that REQUIRES energy (ATP).

Simple Diffusion

Passive transport of smaller, nonpolar molecules (like O2 and CO2) directly across the membrane without protein channels.

Facilitated Diffusion

Passive movement of larger or polar molecules (like sugar and Ca2+) using protein channels.

Osmosis

The diffusion of water molecules across a selectively permeable membrane.

Equilibrium

Condition where molecules are evenly spread out across a space or membrane.

Endocytosis

Active transport process where the cell takes in large molecules or particles.

Exocytosis

Active transport process where the cell removes or releases large waste particles.

Hypotonic Solution

Environment where water moves INTO the cell, causing it to swell.

Isotonic Solution

Environment where water moves IN and OUT at equal rates, keeping the cell balanced.

Hypertonic Solution

Environment where water moves OUT of the cell, causing it to shrink/shrivel.

Homeostasis

Maintenance of a stable internal environment (pH, temperature, glucose, water balance).

Receptor

Homeostatic component (organ or sensor) that detects stimuli and disruptions.

Control Center

Homeostatic component (nervous system/brain/spinal cord) that processes input signals and determines a response.

Effector

Homeostatic component that reacts to stimuli to restore balance.

Negative Feedback

Mechanism where the response reverses the original stimulus to maintain stability (e.g., body temperature, blood pressure).

Positive Feedback

Mechanism where the response intensifies the original stimulus (e.g., childbirth).

Insulin

Hormone released when blood glucose is TOO HIGH to convert glucose into glycogen stored in the liver/muscles.

Glucagon

Hormone released when blood glucose is TOO LOW to convert glycogen back into glucose in the blood.

Buffers

Substances in the blood that prevent it from becoming too acidic or too basic.

Thermoregulation (Too Hot)

Sweating occurs and blood vessels DILATE to release excess heat.

Thermoregulation (Too Cold)

Shivering occurs and blood vessels CONSTRICT to preserve heat.

Cystic Fibrosis

Genetic disorder caused by a problem with the cell membrane, leading to mucus buildup and respiratory infections.