Download Unit 1 - Body Chemistry Notes

Unit 1, Part 2
Chemistry in the Body
Let’s talk Chemistry! But why?
• Food
• Medicine
• Your Body
Chemistry is all over in your body!
• There are THOUSANDS of chemicals in
your body.
• All body processes involve chemistry!
– Movement
– Digestion
– Metabolism
– Respiration
– Pumping of your heart
– Nervous System signals
The Basics…
• Matter – anything that occupies space and
has mass
• Three phases of matter
– Solid: definite shape, definite volume
– Liquid: definite volume, but not shape
– Gas: neither a definite shape or volume
The Basics
• Physical Changes: Do not alter the basic
nature of a substance (chemical formula)
– EX: Bend, Cut, Dissolve, Phase Changes
• Chemical Changes: DO alter the
composition of the substance – a new
chemical formula is formed!
– EX: Digestion of food by enzymes in the body,
Metabolism reactions
The Basics
• The atom: smallest particle that retains
properties of a particular element
– Proton: in nucleus, + charge
– Neutron: in nucleus, no charge
– Electron: orbitals, - charge, smallest
– In neutral atom, # of protons = # of electrons
• Elements identified by number of protons
• Bonding determined by number of valence
(outer) electrons
The Basics
• Compound: when two or more atoms
combine chemically (ex: H2O)
• Ion: formed when an atom has lost or
gained an electron
– Positive ions formed when an electron is lost
– Negative ions formed when an electron is
gained
– Common ions found in the body include Ca+2,
Na+, K+, H+, OH-, Cl-
The Basics
• Chemical reactions are when 2 or more
chemicals combine to create new products
• Types of reactions include…
– Synthesis (in the body, called anabolic)
• A + B  AB
– Decomposition (in the body, called catabolic)
• AB  A + B
– Single Replacement
• A + BC  AC + B
– Double Replacement
• AB + CD  AD + CB
NOTE: anabolic and
catabolic reactions in the
body are collectively
called metabolism!
Which type of reactions are the
following???
The Basics
• Acids vs. Bases
– Acids
• Usually have H+ in the
formula
• Release H+ into solution
• pH less than 7
– Bases
• Usually have OH- in the
formula
• Release OH- into the
solution
• pH greater than 7
Chemistry in the Body
• 96% of all elements in the human body are
from 4 major sources
– Oxygen (65%)
– Carbon (18.5%)
– Hydrogen (9.5%)
– Nitrogen (3.2%)
• One of the most important of these is
Carbon… (show video clip)
Chemistry in the Body
• Organic
– Contains carbon
– Ex: Carbohydrates, lipids, proteins, nucleic
acids
• Inorganic
– No carbon
– Ex: Water, salts, acids, bases
Important Organic Compounds
• CARBOHYDRATES
– Contain carbon, hydrogen, and oxygen in a
1:2:1 ratio
– Include sugars and starches
– Act as a source of cellular fuel
– Classified into 3 groups according to size
• Can be soluble in water
Important Organic Compounds
• Monosaccharide
– Simple Sugar
– Usually used for energy source
– Examples include glucose, galactose, and
fructose (isomers: all have formula of C6H12O6,
but in different combinations & orientations)
Important Organic Compounds
– Other examples with 5 sugars are ribose and
deoxyribose (found in RNA and DNA)
Important Organic Compounds
• In aqueous (water) solutions,
monosaccharides will form ring structures
Important Organic Compounds
• Disaccharide
– Two simple sugars (monosaccharides) are
joined by a dehydration synthesis (loss of
water happens as molecules join)
– Includes sucrose (table sugar), lactose (milk
sugar), and maltose
Important Organic Compounds
This shows a dehydration reaction – water will
be produced as a product!
Important Organic Compounds
Important Organic Compounds
• Polysaccharides
– long branching chains of linked simple sugars
– Includes glycogen in animals, and starch &
cellulose in plants
– Interesting tidbit: glucose needed for muscle
contraction is usually stored as glycogen
Important Organic Compounds
• Both disaccharides and polysaccharides
can be broken down back into
monosaccharides by a hydrolysis reaction
(adding water in)
• Glucose is then commonly used in cellular
respiration (C6H12O6 + O2  CO2 + H2O)
FYI…
• If we eat too many
carbs, and our body
doesn’t immediately
need any ATP,
dietary carbs are
then converted to
glycogen or fat and
stored!
Important Organic Compounds
• LIPIDS
– Contain carbon,
hydrogen, and
oxygen
• Carbon and
hydrogen
outnumber
oxygen
– All types are
insoluble in water
Functions of Lipids in the
Body
•
•
•
•
•
Protection - pads organs
Insulation - prevents heat loss
Regulation – hormones
Structure - cell membrane component
Energy - storage in fat
Important Organic Compounds
• Triglycerides (Neutral Fat)
– Constitutes 95% of the fat in the human body
– Composed of three fatty acids bonded to a
glycerol molecule
– Found in subcutaneous tissue and around
organs, used as fuel
Important Organic Compounds
• Again, fatty acid chains are added to the
glycerol by a dehydration synthesis!
• The bonds along the fatty acid chain can
be oxidized (broken) to release energy.
Important Organic Compounds
• Two types of Fatty Acid Chains…
• Unsaturated
– less than the max # of hydrogens bonded to the
carbons
– End up with double bonds between carbons
– Healthier fats, such as olive oil, peanut oil, &
fish oils
Important Organic Compounds
• Saturated
– Have the max # of hydrogens bonded to the
carbons
– Only single bonds between carbons
– Unhealthy fats, such as beef, pork, & butter
Important Organic Compounds
• Phospholipids
– Composed of two fatty acids and a phosphorus
group bonded to a glycerol molecule
– Chief component of cell membranes
– Phosphorous end is polar (will mix with water),
while fatty acid end is nonpolar (not mix with water)
Important Organic Compounds
• Steroids
– Flat molecules
with four
interlocking
hydrocarbon
rings
– Found in
cholesterol and
certain
hormones
Cholesterol
Testosterone
Estrogen
FYI…
• There are different kinds of
steroids!
• Corticosteroids help with
medical issues like immunity,
metabolism, and blood
volume
• Sex steroids are the same
thing at sex hormones – such
as androgens and estrogens
• Anabolic steroids increase
muscle mass and bone
synthesis… the artificial form
is usually derived from
testosterone
Important Organic Compounds
• PROTEINS
– Made of twisted chains of amino acids
– 50% of organic matter in the body is composed of proteins
– Can be soluble in water
Important Organic Compounds
Functions of Proteins Include:
1. Storage: energy source
2. Transport: hemoglobin; across
membranes
3. Regulatory: hormones
4. Movement: muscles
5. Structural: membranes, hair, nails
6. Enzymes: speed up cellular
reactions (catalysts)
Important Organic Compounds
• Amino Acids – the building
blocks of proteins
– Combination of Nitrogen,
Carbon, Hydrogen, and
Oxygen
– All amino acids have the
same basic structure, but a
different R group attached!
– There are 20 different R
groups found in humans
Structure of Amino Acids
•Amino acids have a
central carbon with 4
things boded to it:
Amino
group
Carboxyl
group
R group
Amino group –NH2
Carboxyl group -COOH
Hydrogen
Side group
-H
-R
(has C & H present,
and sometimes S or O)
Side
groups
Serine
Leucine
Have fun
memorizing
these when
you take
Biochemistry
in college!!!

Important Organic Compounds
• The joining of
amino acids in
a dehydration
synthesis forms
a peptide
bond… the
long chain that
forms is the
protein!
Important Organic Compounds
• Protein shapes determine their function
• If protein denatures (unravels) due to heat
or acidic pH levels, it will lose its function
• There are four different structural levels
that contribute to the shape of a protein
JUST A THOUGHT…
With different combinations of the 20 amino acids,
and the different shapes the molecules can take
on, the potential number of different protein
molecules is enormous!
Important Organic Compounds
• NUCLEIC ACIDS
– Provide blueprint of
life – makes DNA
– Includes a phosphate
group, sugar group,
and base
Nitrogenous base
(A,G,C, or T)
Phosphate
group
Sugar
(deoxyribose)
Important Organic Compounds
– Nucleotide bases
of DNA…
• A = Adenine
• G = Guanine
• C = Cytosine
• T = Thymine
Thymine (T)
Cytosine (C)
Adenine (A)
Guanine (G)
The two
strands of
DNA are held
together with
hydrogen
bonding.
Important Organic Compounds
• RNA is different
than DNA…
– Sugar “Ribose”
used instead of
“Deoxyribose”
– Uracil used
instead of
Thymine
Nitrogenous base
(A,G,C, or U)
Uracil
Phosphate
group
Sugar (ribose)
Important Organic Compounds
• ADENOSINE
TRIPHOSPHATE (ATP)
– Chemical energy used
by all cells
– Energy is released by
breaking high energy
phosphate bond
+ energy