STAREX INTERNATIONAL SCHOOL

NAME :- SANYAM

CLASS :- IX BROLL NO:- 29

TOPIC :- ATOMS AND MOLECULESSUBJECT:- SCIENCE

ATOMS AND MOLECULES

• See pgs. 26-41

CHEMISTERY:-–Science that deals with structure of matter

–Refers to the physiology side of this class

MATTER:- -3 types (solid, liquid and gas)

COMMON CHEMISTRY TERMS

• ATOM:-–Smallest stable unit of matter

• Three subatomic particles:–Protons:–Neutrons:–Electrons:

ATOMS

• Can you calculate the number of protons, neutrons and electrons for ANY element on the periodic table?

• REMEMBER:• Protons = Atomic #• Electrons = # of protons• Neutrons = Atomic Mass # minus

Atomic #• If protons are not equal to electrons the

atom is now known as an ion• Cation = (+) and Anion = (-)

ATOMS (CONTINUED)

• Three types of chemical bonds:– Ionic bonds: between ions– Covalent bonds: shared electrons

– Hydrogen bonds: between two molecules

CHEMICAL BONDS (CONTINUED)

• Nutrients: essential elements and molecules normally obtained through diet

• Metabolites: all molecules that can be processed and broken down by chemical reactions in our bodies– Organic compounds:

• C and H form basis

– Inorganic compounds:• Usually do NOT contain C and H atoms as primary

structure• Most important in body:

– Carbon dioxide (CO2)– Oxygen (O2)– Water (H2O)– Inorganic acids, bases and salts

INORGANIC COMPOUNDS

Inorganic Compounds (continued)

• Water accounts for most of your body weight.

• Proteins, the key structural and functional components of cells, and nucleic acids, which control cell structure and function, work only in solution with the UNIVERSAL Solvent known as Dihydrogen oxide (water).

Acid/Base Terminology and the pH (parts per Hydrogen) Scale

Hydrogen ions (H+) = “Chemical Bad Boy”Highly reactive

Break chemical bondsChange shape of complex moleculesDisrupt cell and tissue functions

Must be regulated preciselypH: concentration of H+ ions in body fluidspH Scale: 0-14

Neutral: solution with pH of 7Acidic: solution with pH below 7Basic: solution with pH above 7

pH of pure water = 7

pH of blood = 7.35-7.45

BLOOD PH• pH of blood = 7.35-7.45• QUICK QUIZ: So is blood neutral,

acidic or basic?– Basic or otherwise known as ALKALINE!

• Large changes in pH of blood can be damaging to cells, tissues and functioning– Acidosis: low blood pH (below 7.35)

• Below 7 = coma

– Alkalosis: high blood pH (above 7.45)• Above 7.8 = uncontrollable, sustained skeletal muscle

contractions

BIOCHEMISTRY

Living things are mainly composed of four kinds of MACROMOLECULES: Proteins, Nucleic Acids, Carbohydrates and Lipids.

PROTEINS• Structurally helps build

certain areas of the body that need extra toughness or strength such as Keratin in nails and hair or cartilage.

• Chemical messengers to keep the brain in contact with the rest of the body.

NUCLEIC ACIDS• Stores information and considered

the body’s blueprint.• Comes in two varieties, DNA or RNA

CARBOHYDRATE Provide energy storageSimple carbs are known as

monosaccharide's or sugarsComplex carbs are known as

polysaccharides or starches

Composed of Carbon and Water.

LIPIDSLong term storage otherwise known as

fatComposed of fatty acids and glycerolSaturated fat= has single carbon

bonding

• Unsaturated fat=

has double bonded carbons

THE END