Download Ions - RCSD

Competency 2
Biochemical Basis of Life
Introduction to Chemistry
• Atoms - smallest particle of an
element that has the elements
properties
• protons (+) = Atomic number
• neutrons (no charge)
• Protons and neutrons together
make up the nucleus
• electrons (-) – used to form
bonds with other elements
Atomic Structure
Electrons
• found in regions of space called electron shells (energy shells)
• each shell can hold a limited number of electrons
• for atoms with atomic numbers of 18 or less, the following rules apply:
• the first shell can hold up to 2 electrons
• the second shell can hold up to 8 electrons
• the third shell can hold up to 8 electrons
• lower shells are filled first
• if the outermost shell is full, the atom is stable
Molecules and Compounds
1. Molecule: when two or more atoms
combine (usually for nonmetals)
Organic compounds all contain
CARBON!!
2. Compound: when two or more atoms
of different elements combine
– Two types
1. Covalent
2. Ionic
Ionic Bond
Ionic Bond
• an attraction between an atoms that are negatively and positively charged
•“opposites attract”
• formed when electrons are transferred from one atom to another atom
Ions
Ion
• an atom that has gained or lost an electron(s)
• an electrically charged atom
• atoms form ions to become stable
• a positively charged ion is
formed when an atom loses
an electron(s)
• a negatively charged ion is
formed when an atom gains
an electron(s)
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Covalent Bond
Formed when atoms share electrons. They “hold hands”.
•Hydrogen atoms form single bonds
•Oxygen atoms form two bonds
•Nitrogen atoms form three bonds
•Carbon atoms form four bonds
2-11
Covalent Bond
COVALENT VS. IONIC
Review
Name and describe the two types of chemical bonds.
What is an ion?
How are ions needed by living things?
Ions allow living organisms to use elements to
construct other compounds necessary for its
survival.
– In a polar covalent bond
• Electrons are shared unequally
between atoms, creating a
polar molecule
• Water is a polar molecule!
(–)
(–)
O
H
(+)
H
(+)
Properties of Water
1. Water is the solvent of life.
Being polar allows water to dissolve
ionically bonded compounds easily.
When compounds dissolve in water
they form a solution.
Na+
–
+
–
–
Cl
+
–
+
–
Ion in
solution
Na+
–
Cl–
+
+
–
–
+
–
+
–
Salt
crystal
–
Properties of Water
2. Hydrogen bonds make water cohesive.
The water molecules “stick” to each
other, so one H2O molecule holds
on to another H2O molecule. This
creates surface tension.
Properties of Water
3. Water is adhesive (holds on to
different/other substances)
ex: molecules can move from a plant’s roots to its leaves
• Capillary Action
Surface tension is also responsible for another
phenomena known as capillary
action. Capillary action occurs when water
climbs upward through a small space, defying
gravity due to the forces of adhesion and
surface tension.
Properties of Water
4. Expansion – water expands when it
freezes, which is opposite to most
substances
– results in ice having a lower density than liquid
water so the ice floats
-- ponds “freeze on top” so organisms are able to
live underneath the ice layer.
-- problem for roads, water will get in cracks of the
pavement and freeze and it will cause the roads
to crack and have potholes.
Properties of Water
5. Water has unique thermal properties
a. high specific heat
b. high boiling point
c. high thermal conductivity
d. good evaporative coolant (sweating)
*also called heat of vaporization
So, as our sweat evaporates, we begin to feel cooler.
What is the pH scale?
pH=power of hydrogen
• Measures the concentration of (hydrogen) H+
ions
• Acids - pH number below 7 and a high
number of H+ ions (low amount of OH-)
• Bases - pH number above 7 and have a high
number of OH- (low amount of H+)
• Pure water is neutral and has a pH of 7.0
pH Scale
Acid rain --contains sulfuric acid and nitric
acid
* Acid rain pH < 5.6
* Acid rain washes away vital
minerals from soil, kills aquatic
organisms & strip nutrients from
plants
Inorganic Substances-do NOT
contain carbon
• Water
–
–
–
–
–
Most abundant in living things
Universal Solvent
Most reactions occur in water
Transports wastes, nutrients, etc.
Absorbs heat
• Oxygen
– Must have in cellular respiration to release energy
• Carbon Dioxide
– Waste product of cellular respiration
• Salts
– Major sources on ions used in metabolic processes
– Na, Cl, K, Ca, Mg, P
Organic substances-all contain
carbon.
Name the 4 major types of organic
macromolecules are:
1.
2.
3.
4.
Carbohydrates
Lipids
Proteins
Nucleic acids
#1- Carbohydrates
• Provides immediate energy for metabolic activites
• Made of C, H, O
• Ratio 1:2:1 (C6H12O6)
• Monosaccharides: simple sugars (glucose)
– These are the building blocks (monomers)
• Disaccharides: two simple sugars combined
together (lactose)
• Polysaccharides: complex carbohydrates
(glycogen, cellulose and starch)
#2- Lipids
• Insoluble in water
• Typically 3 fatty acids and 1 glycerol
(Triglycerides)
• Store energy and have more energy than
carbs
• Made of C, H, O Same elements in carbs,
just don’t have the 1:2:1 ratio.
• Examples-Fats, oils, waxes, steroids,
cholesterol
• Lipids provide insulation, protection,
structure of cell membranes
#3- Proteins
• Provide energy after carbs and lipids
are used up.
• Provide structure, movement of
muscles, transport, regulation,
defense for the body
• Examples-hormones, enzymes,
receptors, and antibodies, hair,
nails, hooves
• Building block (monomer) is the
amino acid
– 20 amino acids of which 12 are
essential
• Made of C, H, O, N
• Held together by hydrogen bonding
(peptide bonds) so heat, pH change,
radiation, etc. affect the bonding
An enzyme is a special
kind of protein
1. Most enzymes are proteins
that can speed up a chemical
reaction and lower the
activation energy needed.
2. Enzymes act as catalysts,
which make a reaction go
faster but without themselves
being used up.
3. Usually end in -ase.
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1. Substratesubstance being
changed by
enzyme
2. Active site- region
on enzyme where
substrate attaches
(this is the enzyme
substrate
complex)
Chemical Reactions and Enzymes
*Enzymes work by either breaking or forming
compounds.
* As an enzyme works, it combines with it
substrate and converts it to products.
Factors that can affect
Enzyme activity
• Temperature-low temps can
make enzymes inactive, high
temps can denature the enzyme
• pH
• Concentrations of substrates or
enzymes
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#4- Nucleic Acids
• Form genes and take part in
protein synthesis
• 2 Kinds:
-DNA (Deoxyribonucleic Acid)
-RNA (Ribonucleic Acid)
• Made of C, H, O, N, P
• Building block (monomer) is a
nucleotide. Nucleotides are
made of a sugar, phosphate, and
a N base.
DNA vs. RNA
• DNA is double stranded • RNA is a single strand
• Contains the sugar
• Contains the sugar
deoxyribose
ribose
• Has nitrogen bases called * Has nitrogen bases called
adenine (A) cytosine (C)
adenine (A) cytosine (C)
thymine (T) guanine (G)
Uracil (U) guanine (G)
ENZYME PRACTICE
1. Label the diagram with these terms: products, active site, enzyme, substrate
substrate
products
Active site
enzyme
2. Answer true of false to the following statements:
F
a. _______ One enzyme can be used for many different types of chemical reactions.
F
b. _______
Enzymes are used only once because they change shape after a reaction occurs.
c. _______
Enzymes speed up reactions.
T
F
d. _______
Raising the temperature will not change the rate of a reaction that uses an enzyme
T
e. _______
Enzyme require specific pH levels.
ATP
ADP
and
Energy!!!
40
Releasing Energy From ATP
• ATP is constantly being used and
remade by cells
• ATP provides all of the energy for
cell activities
• The high energy phosphate bonds can
be BROKEN to release energy
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Releasing Energy From ATP
• Adding A
Phosphate Group
To ADP stores
Energy in ATP
• Removing A
Phosphate Group
From ATP
Releases Energy
& forms ADP
Loose
Gain
42
Cells Using Biochemical Energy
Cells Use ATP For:
• Active transport
• Movement
• Photosynthesis
• Protein Synthesis
• Cellular respiration
• All other cellular
reactions
43
Section 8-1
Adenine
____________
Go to
Section:
ATP
- Adenosine Triphosphate
5-carbon sugar
__________
Phosphate Groups
___________________
44
How energy is released?
Energy
+ +
A phosphate is removed by breaking the
bond between the second and third
phosphate-releasing ENERGY!
45
Importance of ATP
Energy storage chemical for cell processes
Most of ATP is produced via electron
transport chain
Main reason that cells need oxygen: to
allow them to make lots of ATP
Involved in both photosynthesis and
respiration
Photosynthesis
Photosynthesis
6 CO2 + 6 H2O + Sunlight  C6H12O6 + 6 O2
Carbon Dioxide + Water + Sunlight  Glucose + Oxygen
Factors Affecting the Rate of
Photosynthesis
• Amount of
available water
• Temperature
• Amount of
available light
energy
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Photosynthesis has 2 stages:
1. Light Dependent Reaction
*happens in the thylakoids (grana)
• Uses light energy
• Produce Oxygen from water
• Convert ADP to ATP
2. Light Independent Reaction
Also known as the Calvin Cycle or Dark
Reaction
* happens in the open area called the stroma
Photosynthesis Overview
Capturing sunlight happens in the chloroplasts
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Cellular Respiration
C6H12O6 + 6 O2  6 CO2 + 6 H2O + 38 ATP
Glucose + Oxygen  Carbon dioxide + Water + Energy
All cells carry on some form of
cellular respiration. Most plants
and animals require oxygen.
Cellular Respiration
Takes place in the mitochondria
3 Stages of AEROBIC (with
oxygen) Respiration
How much energy does cellular
respiration produce???
1) Glycolysis: Produces 2 ATP per
Glucose
2) Krebs Cycle =2 ATP
3) Electron Transport Chain: 32 ATP
molecules per Glucose
Grand Total = 36 ATP
What happens if oxygen is not
available after glycolysis???
• Instead of pyruvic acid
entering the
mitochondria,
fermentation occurs in
the cytoplasm
• It is known an
anaerobic respiration
• There are 2 types:
Alcoholic
Lactic Acid
Compare Photosynthesis and
Cellular Respiration
Where Does it occur?
Photosynthesis
– Chloroplasts
Cellular Respiration
--Mitochondria
When does it occur?
Photosynthesis
– Daylight Hours
Cellular Respiration
-- At all times
Reactants (what you start
with)
Photosynthesis
– Carbon dioxide
– Water
Cellular Respiration
-- Glucose (sugar)
-- Oxygen
Oxygen
Products (what you end
with)
Photosynthesis
– Glucose (sugar)
Cellular Respiration
--Chemical energy = ATP
Oxygen
THE END