Download Ppt. 7 (Biochemistry)

BIOCHEMISTRY
ATOMS
• ATOM= BASIC UNIT OF MATTER.
• ATOMS CONTAIN:
- PROTONS= SUBATOMIC PARTICLES WITH A
POSITIVE CHARGE. LOCATED INSIDE NUCLEUS.
- NEUTRONS= SUBATOMIC PARTICLES WITH NO
CHARGE. (NEUTRAL). LOCATED INSIDE NUCLEUS.
- ELECTRONS= SUBATOMIC PARTICLES WITH A
NEGATIVE CHARGE. THESE ORBIT AROUND THE OUTSIDE
OF THE NUCLEUS.
ATOMS WITH CHARGES= IONS
• ANIONS= ATOMS WITH A NEGATIVE CHARGE.
• CATIONS= ATOMS WITH A POSITIVE CHARGE.
• PROTONS-ELECTRONS= CHARGE OF ION
BONDING OF ATOMS
• COMPOUND= A SUBSTANCE MADE OF THE
SAME MOLECULES. EX. O2
• MOLECULE= THE PRODUCT OF TWO OR MORE
ATOMS JOINED BY CHEMICAL BONDS.
EX. SALT
IONIC BONDS
• IONIC BONDS ARE FORMED WHEN ATOMS TRANSFER ELECTRONS.
“GIVE & TAKE”
• EX: Na (sodium) gives an electron to Cl (chlorine)
• NaCl is formed (salt)
• Special ionic salts dissolved in water are called electrolytes.
• Ionic solids form geometric crystals or crystal lattices based on the
arrangement of positive and negative ions.
COVALENT BONDS
• COVALENT BONDS ARE FORMED WITH TWO OR
MORE ELEMENTS SHARE VALENCE ELECTRONS.
• RULE 1: ELEMENTS WITH SIMILAR
ELECTRONEGATIVITIES FORM COVALENT
BONDS.
• RULE 2: NON-METALS FORM COVALENT BONDS.
• EX: 2 HYDROGEN ATOMS SHARE ELECTRONS WITH AN
OXYGEN ATOM. THIS FORMS H2O (WATER)
BONDS
• POLAR MOLECULES= SLIGHTLY CHARGED AND
PULLS OTHER ATOMS CLOSER. EX: WATER
• HYDROGEN BONDING= FORMS WITH HYDROGEN
ATOMS PARTICIPATE IN BONDING WITH OTHER
ATOMS.
CHEMISTRY IN BIOLOGY
• CHEMICAL FORMULA= USES SYMBOLS TO SHOW HOW
MOLECULE AND ATOMS REACT TO FORM NEW SUBSTANCES.
• EX:
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PHOTOSYNTHESIS
pH Scale
• pH is short for “potential of hydrogen”
• The scale ranges from 0-14.
• 1-6 is acidic, 7 is neutral, 8-14 is basic.
• Ex. Of an acid: Soda
• Ex. Of a Neutral Substance: Water
• Ex. Of a base: Soap
pH Scale
• ACIDS: THERE ARE HYDROGEN IONS. H+
• BASES: THERE ARE HYDROXIDE IONS. OH• H+ + OH-= H2O (WHICH IS NEUTRAL)
pH Scale
• Indicator= these turn different colors,
depending on the pH of a solution.
• Ex. Litmus paper.
KEY ELEMENTS
• ELEMENT: A TYPE OF MATTER MADE OF ONLY ONE KIND OF ATOM
WHICH CANNOT BE BROKEN DOWN INTO A SIMPLER STRUCTURE.
• THERE ARE SIX ELEMENTS COMMONLY FOUND IN LIVING CELLS.
(SPONCH)
1. SULFUR
2. PHOSPHOROUS
3. OXYGEN
4. NITROGEN
5. CARBON
6. HYDROGEN
THESE ELEMENTS MAKE UP 99% OF ALL LIVING TISSUE.
ORGANIC & INORGANIC MOLECULES
• ORGANIC MOLECULES: THESE
MOLECULES CONTAIN CARBON
• INORGANIC MOLECULES: THESE
MOLECULES DO NOT CONTAIN CARBON
BIOMOLECUES= MOLECULES IN THE BODY
• THE 4 PRIMARY CLASSES OF BIOMOLECULES ARE:
1. CARBOHYDRATES (SUGARS)
2. LIPIDS (FATS)
3. PROTEINS
4. NUCLEIC ACIDS
- EACH OF THESE IS A POLYMER, WHICH IS A LONG CHAIN
OF MONOMERS
CARBOHYDRATES
• CARBOHYDRATES ARE SUGARS. THESE ARE AN ENERGY
SOURCE.
• THE SIMPLEST CARBS ARE MONOSACCHARIDES.
• TWO MONOSACCHARIDES FORM DISACCHARIDES.
• MANY MONOSACCHARIDES FORM POLYSACCHARIDES.
LIPIDS
• LIPIDS ARE FATS.
• THESE ARE MADE UP OF CHAINS OF METHYL UNITS.
• IMPORTANT LIPIDS INCLUDE: WAXES, STEROIDS,
FATTY ACIDS, AND TRIGLYCERIDES.
NUCLEIC ACIDS
• THESE ARE FOUND IN THE NUCLEUS OF A CELL.
• THEY MAKE UP DNA & RNA.
PROTEINS
• THESE ARE MADE OF LONG, LINEAR CHAINS OF
POLYPEPTIDES.
• THE POLYPEPTIDE ITSELF IS MADE OF A CHAIN OF AMINO
ACIDS.
• THERE ARE 20 AMINO ACIDS.
CATALYSTS & ENZYMES
• CATALYST= A SUBSTANCE THAT SPEEDS UP A CHEMICAL
REACTION.
• CATALYSTS LOWER THE ACTIVATION ENERGY TO SPEED UP
THE REACTION.
• ACTIVATION ENERGY= THE AMOUNT OF ENERGY
REQUIRED TO START A CHEMICAL REACTION.
ENZYMES
• ENZYMES= PROTEINS THAT COMBINE
WITH SUBSTRATES TO SPEED UP
CHEMICAL REACTION RATES.
(ENZYMES ARE CATALYSTS)
PROPERTIES OF WATER
• COHESION= WATER MOLECULES ARE ATTRACTED
TO OTHER WATER MOLECULES. (THIS IS WHY ICE
FLOATS, SOME INSECTS CAN WALK ON TOP OF
WATER, ETC.)
• ADHESION= WATER-LOVING MOLECULES
(HYDROPHILIC) ARE ATTRACTED TO WATER.
(THIS IS WHY WATER IS ABLE TO DISSOLVE
SUBSTANCES, LIKE SALT)
• SPECIFIC HEAT= THIS IS THE AMOUNT OF
ENERGY IT TAKES TO CHANGE ONE GRAM OF
WATER ONE DEGREE CELSIUS.
CELLULAR ENERGY
• BOND STRENGTH: A MEASURE OF THE AMOUNT
OF ENERGY REQUIRED TO BREAK A BOND.
• WHEN BONDS BREAK, ENERGY IS RELEASED.
• WHEN BONDS FORM, ENERGY IS STORED.
CELLULAR ENERGY
• FREE ENERGY= ENERGY AVAILABLE TO DO
WORK IS STORED IN THE CHEMICAL BONDS OF
MOLECULES. WHEN A MUSCLE CONTRACTS, IT
CONVERTS THE FREE ENERGY IN GLUCOSE INTO
ENERGY USED BY THE MUSCLE CELLS.
• CELLULAR RESPIRATION= THE PROCESS OF
BREAKING DOWN GLUCOSE FROM THE FOOD
YOU EAT INTO ENERGY THAT YOUR BODY CAN
USE.
CELLULAR ENERGY
• CELLULAR ENERGY IS STORED IN THE FORM OF A
MOLECULE CALLED ATP (ADENOSINE
TRIPHOSPHATE)