The Chemistry of Life What are living creatures

The Chemistry of Life What are living creatures made of? Why do we have to eat? Regents Biology 2006 -2007

Elements of Life § 96% of living organisms is made of: n n carbon (C) oxygen (O) hydrogen (H) nitrogen (N) Regents Biology

Molecules of Life § Put C, H, O, N together in different § ways to build living organisms What are bodies made of? u carbohydrates § sugars & starches proteins u fats (lipids) u nucleic acids u § DNA, RNA Regents Biology

Why do we eat? § We eat to take in more of these chemicals u Food for building materials § to make more of us (cells) § for growth § for repair u Food to make energy § to make ATP Regents Biology ATP

What do we need to eat? § Foods to give you more building blocks & more energy § for building & running bodies carbohydrates u proteins u fats u nucleic acids u vitamins u minerals, salts u water u Regents Biology

Don’t forget water § Water 65% of your body is H 2 O u water is inorganic u § doesn’t contain carbon § Rest of you is made of carbon molecules u organic molecules § § Regents Biology carbohydrates proteins fats nucleic acids

How do we make these molecules? We build them! Regents Biology 2006 -2007

Building large molecules of life § Chain together smaller molecules u building block molecules = monomers § Big molecules built from little molecules u polymers Regents Biology

Building large organic molecules § Small molecules = building blocks § Bond them together = polymers Regents Biology

How to build large molecules § Synthesis building bigger molecules from smaller molecules u building cells & bodies u § repair § growth § reproduction + ATP Regents Biology

Building important polymers Carbohydrates = built from sugars sugar – sugar – sugar Proteins = built from amino acids amino amino acid – acid – acid Nucleic acids (DNA) = built from nucleotides nucleotide – nucleotide Regents Biology

How to take large molecules apart § Digestion taking big molecules apart u getting raw materials u § for synthesis & growth u making energy (ATP) § for synthesis, growth & everyday functions + ATP Regents Biology

Example of digestion ATP ATP starch ATP ATP glucose ATP § Starch is digested to glucose Regents Biology

Example of synthesis amino acids protein § Proteins are synthesized by bonding amino acids Regents Biology amino acids = building block protein = polymer

Carbohydrates Regents Biology

CH 2 OH H HO O H OH H H OH Carbohydrates: Energy molecules Regents Biology 2009 -2010 H OH

Carbohydrates § Building block molecules = sugars sugar - sugar sugar sugar Regents Biology

Carbohydrates § Function: u quick energy u energy storage u structure glucose C 6 H 12 O 6 § cell wall in plants sucrose § Examples u sugars u starches u cellulose (cell wall) Regents Biology starch

Proteins Regents Biology

Proteins: Multipurpose molecules Regents Biology 2006 -2007

Proteins Examples u muscle u skin, hair, fingernails, claws § collagen, keratin u insulin pepsin § digestive enzyme in stomach u insulin § hormone that controls blood sugar levels collagen (skin) Regents Biology

Proteins § Function: u many, many functions § hormones w signals from one body system to another w insulin § movement w muscle § immune system w protect against germs § enzymes Regents Biology w help chemical reactions

Proteins § Building block = amino acids amino amino acid – acid u 20 different amino acids H O H | || —N— —C—C—OH | H variable Regents Biology group There’s 20 of us… like 20 different letters in an alphabet! Can make lots of different words

Lipids: Fats & Oils Regents Biology 2003 -2004

Lipids Concentrated energy molecules Regents Biology 2003 -2004

Lipids § Examples u fats u oils u waxes u hormones § sex hormones w testosterone (male) w estrogen (female) Regents Biology 2003 -2004

Lipids § Function: u energy storage § very concentrated § twice the energy as carbohydrates! cell membrane u cushions organs u insulates body u § think whale blubber! Regents Biology 2003 -2004

Structure of Fat not a chain (polymer) = just a “big fat molecule” Regents Biology 2003 -2004

Saturated vs. unsaturated Regents Biology 2003 -2004

Other lipids in biology § Cell membranes are made out of lipids phospholipids u heads are on the outside touching water u § “like” water u tails are on inside away from water § “scared” of water u forms a barrier between the cell & the outside Regents Biology 2003 -2004

Any Questions? Penguins gone bad! Regents Biology

Old Food Pyramid Regents Biology

New Food Pyramid Regents Biology