Bio 1 - Chap 8 Vocab

Cell

the basic unit of all living things

Cell theory

a fundamental concept of biology that states that all living things are made up of cells, cells are the basic unit of structure & functions in living things, & new cells are produced from existing cells

Cell membrane

a thin flexible barrier that surrounds all cells

Nucleus

a large membrane-enclosed structure that contains genetic material in the form of DNA

Eukaryotes

cells that enclose their DNA in nuclei

Prokaryotes

cells that do not enclose their DNA in nuclei

Cytoplasm

the portion of the cell outside the nucleus

Organelle

structures in a cell that act like specialized organs & preform functions within a cell; “little organs”

Ribosomes

small particles of RNA & protein found throughout the cytoplasm in both eukaryotes & prokaryotes; where proteins are assembled

Endoplasmic reticulum

an internal membrane system in eukaryotic cells; where lipids are synthesized; plays a role in detoxification; has two parts

Golgi apparatus

a stack of flattened membranes; modifies, sorts, & packages proteins & other materials from the ER for storage in the cell or release from the cell

Vacuoles

large, sac-like, membrane-enclosed structures that store materials like water, salts, proteins, & carbohydrates

Lysosomes

small organelles filled with enzymes that break down lipids, carbohydrates, & proteins into small molecules that can be used by the rest of the cell; attack foreign things

Cytoskeleton

helps the cell maintain its shape & is also involved in movement

Chloroplasts

capture the energy from sunlight & convert it into chemical energy stored in food during photosynthesis

Mitochondria

organelle that converts the energy stored in food molecules into compounds that are more convenient for the cell to use

Cell wall

a strong supporting layer around the cell membrane

Lipid bilayer

a double-layered sheet that makes up a cell membrane & gives it a flexible structure that forms a strong barrier between the cell & its surroundings

Selectively permeable

means that some substances can pass across them & others cannot

Homeostasis

a state of relatively constant internal physical & chemical conditions

Diffusion

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

Facilitated diffusion

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

Aquaporins

a water channel protein that allows water to pass right through it

Osmosis

the diffusion of water through a selectively permeable membrane

Isotonic

when the concentration of two solutions is the same

Hypertonic

when comparing two solutions, the solution with the greater concentration

Hypotonic

when comparing two solutions, the solution with a lesser concentration

Osmotic pressure

the force of the net movement of water out of or into a cell

Tissue

a group of similar cells that preform a particular function

Organ

many group of tissues working together to preform a specific function

Organ system

a group of organs that work together to preform a specific function

Receptor

needed to respond to chemical signals, the signaling molecule binds to this, on or in a cell