unit 1, part 2 chemistry in the body. let’s talk chemistry! but why? food medicine your body
TRANSCRIPT
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 source2. Transport: hemoglobin; across
membranes3. Regulatory: hormones4. Movement: muscles5. Structural: membranes, hair, nails6. 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 –NH2
Carboxyl group -COOHHydrogen -H
Side group -R
(has C & H present, and sometimes S or
O)
Amino
group
Carboxylgroup
R group
Side groups
Leucine
Serine
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
Phosphategroup
Sugar(deoxyribose)
Nitrogenous base(A,G,C, or T)
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)
Sugar (ribose)
Phosphategroup
Uracil
Important Organic Compounds
• ADENOSINE TRIPHOSPHATE (ATP)– Chemical energy used
by all cells– Energy is released by
breaking high energy phosphate bond
+ energy