6th Grade Unit 3 Lesson 2 Chemistry of Life (with life processes)

cell membrane (plasma membrane)

surrounds and protects a cell and helps keep the conditions stable inside the cell

cytoplasm

the fluid inside a cell membrane that includes nutrients and flows around all the organelles of a cell

atom

basic building blocks of matter

element

a pure substance made of only one kind of atom

the most common elements in a human body

oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus

molecule

group of atoms held together by chemical bonds

compound

a substance made up of atoms of two or more different elements joined by chemical bonds

nutrients

substances in food that your body needs to grow, to repair itself, to supply you with energy, and perform other life processes

lipid

fat molecule or a molecule that has similar properties; stores energy an organism can use later; does NOT mix with water

protein

molecule made up of smaller molecules called amino acids; used to build and repair body structures and to regulate body processes

amino acids

building blocks of proteins

cellular respiration

the process by which cells use oxygen to produce energy from food

carbohydrate

molecules used as an energy source or energy storage; examples are sugars, starches, and fibers

simple carbohydrates

sugars in fruits, honey, & sugar cane; ex. glucose and sucrose

complex carbohydrates

starches found in grains, potatoes, and some vegetables

nucleic acid

molecule that carries information in cells

phospholipid

a lipid that contains phosphorus; a double layer of these form much of the cell membrane; head end is attracted to water but the tail end repels water

homeostasis

keeping internal conditions stable even when the environment is changing

osmosis

process that moves water through the cell membrane from a higher concentration to a lower concentration

concentration

the spread of something over a given area

ingestion

taking in food/nutrients

digestion

Breakdown of food substances into simpler nutrient molecules that can be absorbed and used

respiration

The process by which cells break down simple sugar molecules to release the energy they contain.

transport

to move or carry from one place to another

excretion

the process by which wastes are removed from the cell/body