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

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

Regents Biology WHAT IS AN ELEMENT??

Regents Biology Elements and Atoms  An element is a pure substance made up of only one type of atom  An atom is the smallest particle of an element that still has all of the properties of that element

Regents Biology

Levels of Organization

Regents Biology What are atoms made up of?  Subatomic particles  Proton –Positively charged particle found in the nucleus  Neutron – Neutrally charged particle found in the nucleus  Electron – Negatively charged particle orbiting the nucleus WcisY

Regents Biology Atoms, Molecules, Compounds  Atoms with the same number of neutrons, protons, and electrons make up an element  Two or more atoms together is called a molecule  When the atoms of a molecule are different elements it is called a compound  Compound – combination of two or more elements

Regents Biology

How many can you count?  Atom:  Element:  Molecule:  Compound:

Regents Biology Element – pure substance made of only one type of atom Atom Subatomic Particles

Regents Biology NOT ALL ATOMS ARE EQUAL

Regents Biology Isotope  Atoms of the same element have a different number of neutrons  Changes mass (makes it heavier)  Charge remains the same  Chemical properties remain the same

Regents Biology  Some isotopes nuclei are unstable and breakdown easily – radioactive isotopes

Regents Biology Uses of Radioactivity  Carbon dating  Figuring out the time of decay for isotopes helps to date fossils and rocks  Radiation as cancer treatment, kills bacteria in food  Used as tracers to follow movements of substances in organisms

Regents Biology Compound Molecule Element Atom Subatomic Particles

Regents Biology HOW ARE MOLECULES AND COMPOUNDS CREATED?

Regents Biology  Atoms can hold a maximum number of electrons in their outer shells  Having the maximum number satisfies an element and it becomes stable  Atoms are always looking to share, lose, or obtain more electrons

Regents Biology Ways to get connected!  Four types of bonds  Ionic bonds  Covalent bonds  Van der Waals forces  Hydrogen bonds

Regents Biology Ionic bonds  An ION is an atom that has a positive or a negative charge  Occurs when an electron is transferred from one atom to another

Regents Biology Ionic Bonds  The atom that loses an electron becomes positively charged! (+)  The atom that gains an electron negatively charged! (–)  (+) attracts (-) like sides of a magnet! WboEVs

Regents Biology

Covalent bonds “Co” = with  Coworker  Cooperate When two atoms share an electron – single bond Share two electrons = double bond Three electrons = triple bond jjQQ

Regents Biology Covalent Bonds  Atoms have different abilities to attract electrons in a covalent bond  The sharing may not always be equal  When sharing is equal the molecule is nonpolar  When sharing is unequal the molecule is polar  Water is an example of a polar molecule

Regents Biology Hydrogen bonds  When partially negative and partially positive regions of a molecule attract the opposite charge in another molecules  INTERmolecular bond!  Between different molecules

Regents Biology Van der waals forces  Occur when sections of oppositely charged regions of atoms come close enough together to attract one another  These forces allow geckos to climb walls

Regents Biology Practice makes perfect On a separate sheet of paper:  Which are elements? Compounds? How do you know? H 2 CO 2 NaCl Fe 2  If a scientist were to study the protons of an atom where would they look?  What is the difference between a covalent and ionic bond?  If an atom loses an electron does it have a negative or a positive charge? How do you know?  How do hydrogen bonds form?

Regents Biology MOLECULES OF LIFE

Regents Biology Do Now  Which are elements? Compounds? How do you know? H 2 CO 2 NaCl Fe 2  If a scientist were to study the protons of an atom where would they look?

Regents Biology Review  Electrons help atoms bond to one other  Two or more atoms of different elements bonded together is called a compound  There are two types of compounds in life: organic and inorganic  What do you think the difference may be between organic compounds and inorganic compounds?

Regents Biology WHAT DO YOU THINK THE DIFFERENCE MAY BE BETWEEN ORGANIC COMPOUNDS AND INORGANIC COMPOUNDS?

Regents Biology ORGANIC COMPOUNDS HAVE CARBON AND HYDROGEN!!!

Regents Biology Molecules of Life  Put C, H, O, N together in different ways to build living organisms  What are bodies made of?  4 Types of macromolecules  carbohydrates  sugars & starches  proteins  fats (lipids)  nucleic acids  DNA, RNA

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

Regents Biology MACROMOLECULE A large molecule – has many, many atoms!

Regents Biology ORGANIC INORGANIC 1. Organic compounds – always contain carbon and hydrogen! 1. Examples:  2. Inorganic compounds - usually lack carbon - when carbon is present it is usually combined with oxygen exs. H 2 O, NaCl, CO 2 TYPES OF MACROMOLECULES

Regents Biology Organic Molecules  Other common elements found in organic molecules

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

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

Regents Biology WHAT HAPPENS TO FOOD AFTER YOU EAT IT??

Regents Biology  Ingest – eat it!  Digest – break it into smaller units  Absorb – into the blood  Distribute – to all the cells in your body  Assimilate – turn in to something else!

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

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

Regents Biology Prefixes  Mono = ________  Poly = _________

Regents Biology  Small molecules = building blocks, monomers  Bond them together = polymers Building large organic molecules

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

Regents Biology Organic Molecules and Digestive End Products Organic MoleculeDigestive End Product(s) carbohydrates Simple sugars (monosaccharides) ProteinsAmino acids lipids (fats)3 fatty acids and glycerol

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

Regents Biology WHAT DOES IT MEAN TO BE DEHYDRATED?

Regents Biology Dehydration Synthesis, Condensation synthesis  Removing water to join monomers into polymers

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

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

Regents Biology Hydrolysis  To lyse, or break, using water

Regents Biology Example of digestion starchglucose ATP  Starch is digested to glucose

Regents Biology Penguins gone bad! Any Questions?

Regents Biology Old Food Pyramid

Regents Biology New Food Pyramid