Ch 3, Sec 3 Chemical Compounds in CellsTarget: To define elements & compounds,

explain how water is important to the function of cells, and identify the functions of carbs, lipids, proteins, & nucleic acids

We are surrounded by trillions of tiny particles, some are made up of elements, others are made of compounds

Air is made up of gases, both elements & compounds. Three gases in air:

- oxygen-nitrogen- carbon dioxide

Elements- any substance that CANNOT be broken down into a simpler substance- ex: oxygen (O2), nitrogen (N2)

- made up of only one kinds of atomAtom

- smallest unit of an element Elements found in living things

- carbon - oxygen- hydrogen - nitrogen- phosphorus - sulfur

Compound- two or elements chemically combined together- ex: carbon dioxide (CO2)

- most elements in living things occur in compound form

Molecule- smallest unit of many compounds - a molecule of CO2 is one carbon atom & two oxygen atoms

Water is compound- H2O (how many hydrogen atoms & how many oxygen atoms are in each molecule of water?)- makes up 2/3 of your body- dissolves chemicals that cells need-most chemical reactions within cells wouldn’t take place without it

- plants couldn’t convert energy from chloroplasts into food

- helps cells keep their shape & size- helps cells keep their temperature regulated

Inorganic compound- does not contain the element carbon - ex: H2O, no carbon in it

NaCl2 (Sodium Chloride, table salt)

Organic compound- contains the carbon element

- ex: carbohydrates, lipids, proteins, nucleic acids

Carbohydrate- energy-rich organic compound made of carbon, hydrogen, & oxygen - ex: sugars & starches

- sugars are produced during food-making process in plants- fruits & vegies have high sugar content- sugar molecules combine, form starches or complex carbohydrates (large molecules) - plant cells store the starch- when we eat potatoes, pasta, rice, the body breaks down the starch into glucose for energy- also important components of cell parts

- cellulose in the cell wall- in cell membrane

Lipids- fats, oils, waxes- energy rich organic compounds made of C2,

H2, O2

- have more energy than carbs- cells stores energy here for later use- make up most of the cell membrane

Proteins- large organic molecules made of

- carbon - hydrogen- nitrogen - oxygen- sometimes sulfur

- foods high in protein: eggs, fish, meat, nuts, beans

- Structure of proteins- made of smaller molecules called

amino acidsAmino acids

- a small molecule linked chemically to other amino acids to form proteins- like letters of the alphabet, they can be combined together to make different proteins- ex: lysine, tyrosine, leucine (put these together and it makes different) - 20 amino acids

- Function of proteins- most of cell structure is made of

proteins (parts of cell membrane, many organelles)

Enzyme- type of protein that SPEEDS up chemical reactions in living things- without enzymes, chemical reactions would take too long for cells to do their job or not happen at all- ex: saliva has enzymes in it to help break down food & aid in digestion

Nucleic Acids- long organic molecules- contain instructions for cells to carry out their functions of life- made of

- carbon - oxygen- hydrogen - nitrogen - phosphorous

- two types- DNA (deoxyribonucleic acid)

- genetic material passed on from parent to

offspring- directs all cell’s functions- mostly contained in chromatin in nucleus

- RNA (ribonucleic acid)- aids in production of proteins- found in cytoplasm of cell, &

nucleus