Human Bio Test 1 Revision

cell

The smallest unit that is capable of performing life functions.

Prokaryotic

Does not have a nucleus.

Eukaryotic

Contains organelles surrounded by membranes and has a nucleus.

cell membrane

A semipermeable cell structure that controls which substances can enter or leave the cell.

cytoplasm

Thick fluid within the cell that supports organelles.

Cytoskeleton

Network of protein fibers in the cytoplasm responsible for cell movement and stability.

mitochondria

Rod-shaped structure that produces energy through aerobic respiration of glucose.

Nucleus

Largest organelle that directs cell activities and contains genetic information.

Nucleolus

Found inside the nucleus and produces ribosomes.

Endoplasmic Reticulum (ER) (rough)

Involved in protein production, storage, and transport of materials.

Endoplasmic Reticulum (smooth)

Moves materials around the cell and produces lipids.

Golgi Body/Apparatus

Packages, modifies, stores, and secretes cellular products.

Lysosome

Membrane-bound bag of digestive enzymes that destroy foreign bodies and unwanted organelles.

Vacuoles

Membrane-bound sacs involved in storage, digestion, and waste removal.

Ribosomes

Small sphere-like structures involved in making proteins.

Centrioles

Composed of microtubules involved in cell division.

Fluid mosaic model

Describes the arrangement and movement of molecules that make up a cell membrane.

Phospholipid bilayer

Double layer of lipid molecules that allows flexibility and serves as a protective barrier.

Functions of cell membrane

Physical barrier, regulation of material passage, sensitivity, and support.

channel proteins

Form a tunnel through which molecules may pass.

carrier proteins

Change shape to allow molecules to pass through.

glycoproteins and glycolipids

Function in cell recognition.

integral proteins

Span the membrane.

peripheral proteins

Are located on one side or the other of the membrane.

cholesterol

Gives the cell membrane extra support and maintains fluidity.

intracellular fluid

Fluid inside the cell, while extracellular fluid is outside the cell.

cell theory

All living things are composed of cells, cells are the basic units of structure and function, and new cells arise from existing cells.

selective permeability (cell membrane function)

Controls what enters and leaves the cell.

physical barrier (cell membrane function)

Separates intracellular and extracellular fluid.

sensitivity (cell membrane function)

Contains receptors for monitoring changes.

support (cell membrane function)

Provides support to the cell.

vesicles

Small membrane sacs that specialize in moving products into, out of, and within a cell.

passive transport

Transport that requires no energy.

active transport

Transport that requires energy to move substances against the concentration gradient.

diffusion

Random spreading out of molecules from high to low concentration.

net diffusion

Movement continues until concentrations equalize.

factors affecting diffusion

Steepness of the concentration gradient, molecular size, temperature.

hypertonic

Higher solute concentration (e.g., saltwater).

hypotonic

Lower solute concentration (e.g., distilled water).

isotonic

Equal concentration of two solutions.

osmosis

Diffusion of water through a selectively permeable membrane.

Facilitated diffusion

Movement of specific molecules across membranes via carrier proteins.

high concentration

When molecules are more crowded.

plasmolysed

Cells that are losing water.

turgid

Swollen cells.

gas diffusion

Gases move from high to low concentration.

how is concentration gradient for oxygen maintained?

By blood flow through capillaries and breathing.

Emphysema (cause)

Long term exposure to irritating particles.

Emphysema (effect)

Damage to alveoli reduces gas exchange.

pneumonia cause

Infection of the lungs by organisms.

pneumonia effect

Inflammation fills alveoli, reducing exchange area.

pulmonary circulation

Takes deoxygenated blood to lungs and returns oxygenated blood to heart.

systemic circulation

Takes oxygenated blood to body and returns deoxygenated blood to heart.