Cells & Tissues

Cells

Building block of life.

Nucleus

Control center of the cell. Contains DNA.

Plasma Membrane

Fragile, transparent barrier that contains the cell contents and seperates them from the surrounding environment. Contains two lipid layers aranged "tail to tail" where protein molecules float. Imperm

Cytoplasm

Cellurlar material outside the nucleus and inside the plasma membrane.

Cytosol

Semitransparent fluid that supsends the other elements.

Rough ER

Studded with ribosomes. All building materials of cellurlar membranes are formed here.

Smooth ER

Functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs.

Lysosomes

Break down nonusable cell structures and most foreign substances that enter the cell.

Peroxisomes

Molecular oxygen to detoxify a number of poisonous substances including alcohol and formaldehyde. It disarms free radicles.

Mitochondria

Threadlike organelles. Forms ATP.

Cytoskeleton

Elaborate structure of proteins that extend throughout the cytoplasm. Shapes and supports the cell. Supports other organelles and provides machinery needed for intracellurlar transport and cell moveme 

Selective Permeability

Barrier that allows some substances to pass through it while excluding others.

Simple Diffusion

 Process by which molecules tend to scatter themselves through the cell without an assistance. Lipid solubles and small molecules do this.

Osmosis

Diffusion of water through a selectively permeable membrane such as the plasma membrane. Passes through the pores of the membranes.

Facilitated Diffusions

Protein carrier is needed to transport larger molecules through the cell.

Isotonic diffusion

Water molecules move in and out of the cell at the same rate and cells stay the same shape.

Hypertonic solution

Water leaves a cell faster than water goes into a cell causing the cell to shrink.

Hypotonic solution

Water enters a cell faster than water going out of a cell causing the cell to swell.

Active Transport

When ATP is used to move substances through cells.

Solute pumping

Protein carriers use ATP to get through the plasma membrane.

Bulk Transport

Way to move substances that cannot be moved in any other way.

Exocytosis

Moves substances out of the cell. The sac of substances merge into the plasma membrane and then ruptures, spilling all the contents out of the cell.

Phagocytosis

Eats sacs of substances outside of the cell. White blood cells do this.

Pinocytosis

Plasma membrane inaginates to form a tiny pit and then its edges fuse aroudn the droplet of extracellular fluid containing dissolved proteins or fats.