Bio 1 Chapter 8 Vocab

32 terms

cell

basic units of all livings things

Cell theory

fundamental concept of biology

Cell membrane

thin flexible barrier of the cell

Nucleus

a large membrane-enclosed structure that has DNA

Eukaryotes

cells that enclose DNA in nuclei

Prokaryotes

cells that DO NOT enclose DNA in nuclei

Cytoplasm

portion of the cell outside the nucleus

Organelles

specialized structure that performs important cellular functions within a cell

Ribosomes

small particles of RNA and protein found in cytoplasm in both cells

Endoplasmic reticulum

eukaryotic cells contain an internal membrane system

Golgi apparatus

proteins produced in the rough ER move next into an organelle, stack of flattened membranes

Vacuoles

large, sac-like, membrane-enclosed structures

Lysosomes

small organelles filled with enzymes

Cytoskeleton

network of protein filaments

Chloroplast

biological equivalents of solar power plants

Mitochondria

power plants of the cell

Cell wall

strong supporting layer around the membrane

Lipid bilayer

gives cell membranes a flexible structure that forms a strong barrier between the cell and its surroundings

Selectively permeable

some substances can pass across them and others cannot

Homeostasis

state of relatively constant internal physical and chemical conditions

Diffusion

the process by which particles move from an area of higher concentration to an area of lower concentration

Facilitated diffusion

molecules that cannot directly diffuse across the membrane pass through special protein channels

Aquaporins

water channel proteins that allow water to pass right through them

Osmosis

diffusion of water through a selectively permeable membrane

Isotonic

same strength

Hypertonic

above strength

Hypotonic

below strength

Osmotic pressure

driven by differences in solute concentration, the net movement of water out of or into a cell produces a force

Tissue

group of similar cells that perform a particular function

Organ

many groups of tissue that work together

Organ system

group of organs that work together to perform a specific function

Receptor

on or in a cell; specific protein to whose shape fits a specific molecular messenger; an example is a hormone