1. Biochemistry
The Molecules of Life

2. The Molecules of Life
Carbon – The main ingredient of organic
molecules

3. The Molecules of Life

4. Carbon has only 4 electrons in its last energy level: 4 valence e⁻
The Molecules of Life
Carbon has only 4 electrons in its last
energy level: 4 valence e⁻
Can hold up to 8 e⁻ in its last energy level
It can hold up to 4 bonds with other atoms

5. Carbon can form bonds with one or more carbon atoms
The Molecules of Life
Carbon can form bonds with one or more carbon atoms
Produces an endless variety of carbon skeletons

6. The Molecules of Life
Organic Molecules – Carbon based molecules
Inorganic Molecules – Non-carbon based
molecules
H₂O, O₂, NH₃ (ammonia)
Hydrocarbons – are organic molecules that are
composed of only carbon and
hydrogen
Many hydrocarbons are important fuels

7. Methane (CH₄) one the most abundant hydrocarbons in natural gas
The Molecules of Life
Methane (CH₄) one the most abundant
hydrocarbons in natural gas
Used to heat homes

8. Biomolecules may be composed of hundreds or
Monomers and Polymers
Biomolecules may be composed of hundreds or
even millions of atoms
Monomers – Large molecules built from many
similar smaller molecules
Polymers – Monomers linked together into long
chains
Polymers can be straight, branched, or folded back
on themselves.

9. Four Main Categories for Large Molecules
Carbohydrates
Lipids
Proteins
Nucleic Acids

10. Carbohydrates Provide fuel and building material for our bodies
Can provide energy minutes after consumption or stored away for later use…..

11. An organic compound made up of sugar molecules
Carbohydrates
An organic compound made up of sugar molecules
Contain: Carbon
Hydrogen Ratio: 1C : 2H : 1 O
Oxygen
Basic carbohydrate formulas: CH₂O
The core of most sugar molecules found in nature are ring shaped

12. Carbohydrates Monosaccharide's – simple sugar contain just one
sugar unit
Glucose
Fructose Key suffix –ose
Galactose
Found in sweets
Honey has both Glucose and Fructose

13. Carbohydrates
Glucose exist in both straight-chain and ring shaped forms
Sugar molecules, glucose, are the main fuel supply for cellular work
Cells break down glucose molecules and extract their stored energy (we will learn later)
Cells also use the carbon skeletons of monosaccharide's as raw materials for manufacturing other kinds of organic molecules

14. Carbohydrates
If not used immediately by cells usually incorporated into larger carbohydrates or may be used to make fat molecules

15. Carbohydrates Disaccharides – “double sugar”; using dehydration
reaction form two monosaccharide's.
Sucrose – Most common disaccharide
Glucose + Fructose Molecules
Major “carbo” in plant sap
Maple Tree

16. Carbohydrates
Table sugar is Sucrose processed from sugarcane or roots of sugar beets
Same as Monosaccharide’s, sucrose is broken down into glucose / fructose and used right away.
Body CAN store glucose in larger molecules for later use.

17. Carbohydrates Polysaccharides
Long polymer chains made up of simple sugar monomers
AKA complex Carbs
Starch – A polysaccharides found in plant cells that
consists entirely of glucose monomers.
Starch chains (in a plant) coil up like a telephone cord
Plant cells use starch: sugar; like animals to perform work and as raw materials for building other molecules

18. Carbohydrates
Starch
Humans (animals) break down starch to perform work

19. Carbohydrates Polysaccharides Animal cells DO NOT contain starch
Glycogen – in animals; like starch; is a chain of many
glucose monomers
This is more highly branched than a starch molecule
In humans glycogen is stored as granules in the liver (use later) and muscle cells (use now)

20. Carbohydrates Cellulose (In Plants) A polysaccharide
Serve as building material
Protect cells, stiffing the plant
Prevents the plant from falling over
Like starch / glycogen, cellulose is also made of glucose monomers
Form cable like structures in plants
Like in celery and broccoli

21. Carbohydrates
Most animals and humans can’t digest cellulose, because we lack the necessary enzymes to break the bonds between the glucose molecules
AKA – Fiber
Fiber passes right through digestive system unchanged
Keeps digestive system healthy
Not a nutrient

22. Carbohydrates Cows and termites CAN derive nutrients from cellulose
Microorganisms inside the digestive tract of cows & termites break down cellulose

23. Carbohydrates Almost all carbohydrates are Hydrophilic (water loving)
Due to the hydroxyl groups in their sugar units

24. Carbohydrates
Monosaccharide's and disaccharides dissolve readily in water
Cellulose and some forms of starch do not
Example: Cotton is still hydrophilic, still giving them the ability to absorb water

25. Lipids: Fats and Steroids
A class of water avoiding compounds
Hydrophobic – Water avoiding molecule
Lipids act as boundary that surrounds and contains the watery contents of your cells

26. Lipids: Fats and Steroids
Consists of a 3 – carbon backbone called glycerol attached to 3 fatty acids, which contain long hydrocarbon chain

27. Lipids: Fats and Steroids
Fatty tissues cushion organs and insulates your body
Also an energy source
Saturated Fat – Fat in which all 3 fatty acid chains
contain the maximum possible number
of hydrogen atoms
Solid at room Temperature
BAD FAT

28. Lipids: Fats and Steroids
Unsaturated Fat – Contains less than the maximum
number of Hydrogen atoms in one
or more of its fatty acid chains
Because Carbon atoms are double bonded to each other
Liquid at room temperature
GOOD FAT

29. Lipids: Fats and Steroids
A lipid molecule in which the Carbon skeleton forms 4 fused rings
All steroids have a core set of 4 rings but are different by kind and location of functional group

30. Lipids: Fats and Steroids
Steroids are lipids because they are hydrophobic (same as fat)
Differences from fat:
Circulate in your body as chemical signal
Estrogen a female sex hormone
Testosterone a male sex hormone
Testosterone

31. Lipids: Fats and Steroids
Cholesterol
Best known an infamous steroid
An essential molecule found in the membranes that surround your cells
Also a starting point from which your body produces other steroids
Cholesterol is also linked to increase cardiovascular disease
HDL – Good Cholesterol (60 and above)
LDL – Bad Cholesterol (Less than 100)

32. Proteins
A polymer constructed from a set of just 20 kinds of monomers called amino acids
There are tens of thousands of different kinds of proteins
The diversity enables proteins to provide the molecular tool kit for everything cells do.
Responsible for almost all functioning of organisms
Form structure:
Hair, Fur, and Muscles

33. Proteins Proteins are also part of the circulatory system
Defending against illness
Provide “long term” storage for nutrients
Some proteins control chemical reactions in a cell

34. Proteins: Amino Acids
A monomer consist of a central carbon atom bonded to 4 partners
One partner is a Hydrogen atom
Two others are a carboxyl and Amino group (Notice N)
The difference between amino acids is the “side group” or R-Group
This R group is responsible for the particular chemical properties of each amino acid

35. Proteins Amino Acids Polypeptide – Chains of amino acids
Created by dehydration reaction between an amino group and the carboxyl group of the next amino acid

36. Proteins Proteins are composed of one or polypeptide chains
Most polypeptide chains are at least 100 amino acids in length
20 different amino acids
These combinations make up an enormous number of combinations
If the number of possible proteins with five amino acids is 20×20 ×20 ×20 ×20 = 20⁵= 3,200,000.

37. Proteins
To be functional proteins MUST consist of polypeptide chains precisely twisted, folded, and coiled into unique shapes.
Although not fully understood the shapes of protein molecules can be related to water
Hydrophilic side on the outside and hydrophobic on the inside
Remember protein is made in water

38. A denatured protein loses its shape and ability to work
Proteins
Denaturation – the unraveling and losing of proteins
normal shape
Caused by an unfavorable change in pH or temperature
“egg white” changes from clear to white because temperature increase, denaturizes protein
A denatured protein loses its shape and ability to work

39. Proteins Enzymes Proteins that speed up specific reactions in cells
Activation Energy – Minimum amount of energy
required to trigger a chemical
reaction
To start a chemical reaction, you must 1st weaken the chemical bonds in the reactant
One way to speed up a reaction is to heat up the mixture of molecules
Hotter molecules collide with enough force to weaken bonds
Cooler molecules collide with less energy

40. Proteins
Enzymes
In our body heating up a cell would cause many simultaneous reactions that can destroy a cell
Catalysts – compounds that speed up chemical
reactions
Enzymes are the main catalysts
Enzymes provide a way for reactions to take place at cells normal temperatures
Each enzymes catalyze a specific kind of chemical reaction
Enzymes that are present and active determine which reaction will occur

41. Proteins How Enzymes Work Lock and Key Model
Substrates – A specific reactant acted on by an enzyme
Active Site – A part of an enzyme that a substrate fits
VERY SPECIFIC
Not a rigid “fit”

42. Proteins - How Enzymes Work
A substrate enters; the active site changes slightly
This places certain functional groups of the active site in position to catalyze the reaction
Change of shape may also weaken substrate bonds
Enzyme can also accept two reactant molecules into adjacent sites at one time
This enables them to react more easily

43. Proteins - How Enzymes Work
Enzymes structure and shape are essential to its function (From & Function)
Enzymes, like protein are affected by temperature, pH, and concentration of that enzyme

44. Properties of Water
Cohesion – a property of water; water molecules are attached to one another
Cohesion is formed by Hydrogen bonds

45. Properties of Water
Adhesion – water’s hydrogen bonds, bond to other substances or attraction between
unlike molecules
Capillary Action – the tendency of water to rise in a thin tube
It is a combination of both cohesion and adhesion
Both are also properties of water

46. Properties of Water
Capillary Action
Adhesion