Download presentation
1
What are organic molecules?
Molecules of Life What are organic molecules? Compounds that contain carbon What are biological molecules? Nucleic Acids Carbohydrates Lipids Proteins
2
Organic Molecules What is a cell made up of mostly?
Mostly water, but what else? Carbon based molecules Why is carbon so significant for these molecules?
3
Each carbon acts as an ‘intersection’
With 4 different branch points Creates endless variety of (organic) carbon molecules Vary in length
4
Diversity of Carbon-Based Molecules
Different location of double bonds Unbranched or branched Rings
5
Methane ……….. Is a hydrocarbon What is a hydrocarbon?
& Hydrogen Methane is the simplest
6
Functional Groups Groups of atoms known as functional groups can give special properties on carbon-based molecules. Carbon is a central element to life because most biological molecules are built on a carbon framework.
7
Functional Groups For example, the addition of an –OH group to a hydrocarbon molecule always results in the formation of an alcohol.
8
Functional Groups
9
Making Polymers Dehydration* Reaction - links molecules together
A covalent bond forms between molecules and water is removed Reaction by which monomers are joined to form larger molecules Examples: *Also called a condensation reaction
11
Breaking Polymers Hydrolysis reaction – breaks down larger molecules
Water is added to a larger molecule to split off a smaller molecule. Reaction involves breaking a covalent bond by adding water Reverse of a dehydration reaction
13
Biological Molecules Food ‘Carbs’ Structural Sugar Storage Glucose
Enzymes Glycogen Antibodies Cellulose Oils Fatty acids (sat & unsat) DNA RNA Butter
14
Carbohydrates Carbohydrates are formed from the building blocks or monomers of simple sugars, such as glucose. These monomers can be linked to form larger carbohydrate polymers, which are known as polysaccharides or complex carbohydrates.
15
Carbohydrates What type of sugar is found in the following?
Small (simple) sugar molecules Examples? Monosaccharides Glucose Fructose Disaccharides Lactose Sucrose Long starch molecules in pasta, potatoes Examples? Polysaccharides Starch Cellulose These are our primary sources of dietary energy In plants, carbs used as building material
16
Monosaccharides What type of sugar is found a sports drink?
Glucose What type of sugar is found in fruit? Fructose
17
What about honey? Its really sweet? Why?
It contains both glucose and fructose
18
Glucose and Fructose Have the same formula… C6H12O6
Why are they ‘different’? They are isomers
19
Form rings in aqueous solutions
Which sugar is this? Glucose
20
Disaccharides Are ‘double sugars’ What are they constructed from?
2 monosaccharides
21
Disaccharides Maltose: glucose and glucose Lactose: galactose and
Sucrose: glucose and fructose
22
Lactose, another disaccharide
Some people have trouble digesting lactose Its a condition called lactose intolerance Missing gene for lactase enzyme
23
Sucrose Common table sugar Sugar cane Roots of sugar beets
The most common disaccharide is sucrose, what do you know it as? Common table sugar What plants do we use to extract table sugar? Sugar cane Roots of sugar beets
24
Polysaccharides Are long chains of sugar units Starch Glycogen
(polymers) (monosaccharides) What are some polysaccharides? Starch Glycogen Cellulose
25
Starch Glycogen Cellulose
Potatoes and grains are major sources of starch in the human diet Glycogen Liver, muscle cells break down glycogen to release glucose when needed for energy Cellulose Structural component, dietary fiber
26
Complex Carbohydrates
Four polysaccharides are critical in the living world: starch glycogen cellulose chitin
27
Four Complex Carbohydrates
Potato (b) Liver (c) Algae (d) Tick Starch Glycogen Cellulose Chitin
28
Biological Macromolecule: Carbohydrates
Function: Monomer: Dietary energy Storage Plant structure Examples: Monosaccharides (simple sugars) (glucose, fructose) Disaccharides (double sugars) (maltose, lactose, sucrose) Polysaccharides (long polymers) (starch, glycogen, cellulose)
29
Starch is the nutrient storage form of carbohydrates in plants.
Glycogen is the nutrient storage form of carbohydrates in animals.
30
Lipids Butter, lard, margarine, and salad oil
Do these lipids mix well with water? Lipids do not possess the monomers-to-polymers structure seen in other biological molecules; no one structural element is common to all lipids. Among the most important lipids are the triglycerides, composed of a glyceride and three fatty acids. Most of the fats that human beings consume are triglycerides.
31
Lipids This diverse group of molecules includes? Fatty acids Steroids
(energy storage, cushioning, insulation) A biological compound consisting of three fatty acids linked to one glycerol molecule Steroids (cholesterol, in membranes) Characterized by a carbon skeleton consisting of four rings with various functional groups attached
32
Fatty Acids Technically called? triglycerides A fat molecule: Glycerol
‘saturated’ ‘unsaturated’ Double bond ‘unsaturated”
33
Unsaturated fatty acids
(plant oils) Have less than the maximum number of hydrogens bonded to the carbons Saturated fatty acids (butter) Have the maximum number of hydrogens bonded to the carbons
34
Double Bonds What is the significance of the number of double bonds in the hydrocarbon tails? Unsaturated fats tend to be liquids at room temperature Example? vegetable oils Impact on health? unsaturated fats are safer Saturated fats are solid at room temperature Example? butter and lard Impact on health? Saturated fats in the diet can lead to heart disease
35
Steroids How does the structure differ from fatty acids?
Ring structure, various functional groups How does the function differ from fatty acids? Functional groups affect function causes differences between the hormones estrogen and testosterone Example? (anatomical and physical development) cholesterol in membranes
36
Steroids (a) Four-ring steroid structure (b)
Side chains make each steroid unique testosterone estrogen cholesterol
37
Phospholipids A third class of lipids is the phospholipids, each of which is composed of two fatty acids, glycerol, and a phosphate group. The material forming the outer membrane of cells is largely composed of phospholipids.
38
Waxes A fourth class of lipids is the waxes, each of which is composed of a single fatty acid linked to a long-chain alcohol. Waxes have an important “sealing” function in the living world. Almost all plant surfaces exposed to air, for example, have a protective covering made largely of wax.
39
Biological Macromolecule: Lipids
Function: Monomer: Long term energy storage Hormones Examples: Fats, oils (triglycerides) (butter, lard, margarine, salad ols) Steroids (lipid rings) (cholesterol, hormones)
40
Proteins What is a protein? Proteins are an extremely diverse group of
biological molecules composed of the monomers called amino acids. Constructed from a set of 20 different monomers
41
Proteins Sequences of amino acids are strung together to produce polypeptide chains, which then fold up into working proteins. Important groups of proteins include enzymes, which hasten chemical reactions, and structural proteins, which make up such structures as hair.
42
Types of Protein
43
The Monomers What does each amino acid monomer consist of?
Amino group Carboxyl group A central carbon atom Bonded to four covalent partners Each side group is unique Identifies each amino acid’s characteristics
44
Examples of 2 different amino acids and their side groups
45
Beginnings of a Protein
The linkage of several amino acids . . . ala gln ile ala gln ile A typical protein would consist of hundreds of amino acids . . . produces a polypeptide chain like this:
46
Structure Proteins are complex! Primary Secondary Tertiary Quaternary
To simplify, we’ll describe them in terms of 4 levels of structure: Primary a particular # and sequence of amino acids Secondary turns and folds, alpha helix, pleated sheet Tertiary irregular loops and folds, 3-D shape Quaternary 2 or more polypeptides combined
47
Levels of Protein Structure
Four Levels of Structure In Proteins (a) Primary structure The primary structure of any protein is simply its sequence of amino acids. This sequence determines everything else about the protein’s final shape. amino acid sequence (b) Secondary structure Structural motifs, such as the corkscrew-like alpha helix, beta pleated sheets, and the less organized “random coils” are parts of many polypeptide chains, forming their secondary structure. alpha helix random coil beta pleated sheet (c) Tertiary structure These motifs may persist through a set of larger-scale turns that make up the tertiary structure of the molecule folded polypeptide chain (d) Quaternary structure Several polypeptide chains may be linked together in a given protein, in this case hemoglobin, with their configuration forming its quaternary structure. two or more polypeptide chains
48
Biological Macromolecule: Proteins
Monomer: Function: Amino group Carboxyl group Many! Change rate of reaction Carry molecules Cell communication Examples: Enzyme (lactase) Transport (hemoglobin) = 20 amino acids Defense (antibodies)
49
Biological Molecules
50
Nucleic Acids What are nucleic acids?
The cells information storage molecules There are two types of nucleic acids DNA, deoxyribonucleic acid RNA, ribonucleic acid These ‘work together’ to synthesize protein
51
Synthesizing Protein What does DNA do?
It carries instructions for building all the proteins
52
What does DNA do? Information in DNA is transcribed into RNA
53
What does RNA do? RNA acts as an intermediary in the protein-making process DNA RNA Protein
54
What else does RNA do? RNA then translates the (transcribed) information into the primary structure of proteins What is the primary structure of proteins?
56
What does protein do? Proteins carry out cell activities
57
Structure What is the structure of nucleic acids?
They are polymers of nucleotides What do the nucleotides contain? Phosphate group Nitrogen base Sugar (Deoxyribose)
58
What do DNA nucleotides contain?
Each DNA nucleotide has one of the following bases: 2 1 Adenine (A) Thymine (T) Cytosine (C) 4 3 Guanine (G) Which one is which? Match the numbers to the base
59
Polymers of nucleotides
Linked into long chains Nucleotide Called polynucleotides or DNA strands A sugar-phosphate backbone joins them together Bases Activity: Nucleic Acid Structure
60
2 DNA strands form helix How does this happen? A always binds with T
Via complementary binding (and hydrogen bonding) A always binds with T C always binds with G
61
RNA, different from DNA It has the base uracil (U) instead of thymine (T) in DNA The RNA sugar has 2 OH groups vs 1 in DNA (Ribose vs deoxyribose)
62
Biological Macromolecule: Nucleic Acids
Monomer: Function: Information storage Phosphate Examples: DNA Sugar Base RNA Could this be a monomer for RNA?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.