Fig. 4.2: in 1953 Stanley Miller Simulated What Were Thought to Be Environmental Conditions in the Prebiotic Earth

I. Chapter 5 Summary

A. Simple Sugars (CH2O)n: 1. One C contains a carbonyl (C=O) rest contain -OH 2. Classification by functional group: aldoses & ketoses 3. Classification by number of C's: trioses, pentoses, hexoses 4. Stereochemistry: all sugars have D conformation 5. Cyclic structure: -OH bonds to carbonyl carbon ==> 5- or 6-member ring B. Disaccharides: 2 simple sugars joined by "glycosidic" bond between - OH of one and carbonyl of another 1. Table sugar 2 . M a l t o s e 3. Lactose C. Polysaccharides 1. Food Storage: starch and glycogen are polymers of glucose 2. Structural: cellulose is polymer of glucose 3. Differ in conformation of carbonyl C where sugars are joined II. Nucleotides & Nucleic Acids A. Nucleotides: Base-sugar-phosphate B. Nucleic Acids 1. Nucleotide polymer connected by phosphodiester bonds 2. RNA (RiboNucleic Acid)-nucleotides contain ribose sugar 3. DNA (DeoxyriboNucleic Acid)-nucleotides contain 2!-deoxy-ribose sugar III. Lipids A. Glycerides 1. Triglycerides: 3 fatty acids bonded to 3 -OH's of glycerol by ester bonds 2. Phospholipids: Diglycerides and Amphipathic (have polar and nonpolar groups) 3. Phospholipid bilayer B. Cholesterol-sterol lipid

Fig. 4.2: In 1953 Stanley Miller simulated what were thought to be

Figure 4-02 environmental conditions in the prebiotic earth.

1 Chapter 5: Biological Building Block Molecules (Monomers) and Macromolecules

Complex Polymer Monomer Simple Polymer (Macromolecule) Monosaccharide Polysaccharide Oligosaccharide (Simple Sugar) (Complex Carbohydrate) Nucleotide Oligonucleotide Nucleic Acid Polypeptide Amino Acid Peptide Protein

What do Macromolecules Do?

Carbohydrates & Lipids: Important Functions fuel molecules for energy structural roles Nucleic Acids: Store, Transmit, and Decode Hereditary Information (also some structural roles) Proteins: Perform an incredible number of functions! structural proteins transport proteins enzymes hormones & signaling molecules storage proteins receptor proteins contractile & motor proteins defense proteins

2 Fig. 5.2: Common Features of Macromolecules 1. Proteins, carbohydrates and nucleic acids are complex polymer molecules created by joining together building blocks called monomers

5 6 7

Monomers are linked by a condensation reaction (a dehydration reaction that produces H2O)

Fig. 5.2 Common Features of Macromolecules 2. Protein, carbohydrate and nucleic acid polymer molecules are broken down into monomers by hydrolysis of the bonds between monomers

Hydrolysis adds a water molecule, breaking a bond

3 Common Features of Macromolecules 3. Protein, carbohydrate and nucleic acid polymer molecules can fold into complex 3-dimensional shapes (specific shape depends on sequence of monomers)

Ionic bonds, Hydrogen bonds and Van der Waal’s interactions are important in specifying and maintaining shape

Common Features of Macromolecules 4. Protein, carbohydrate, lipids and nucleic acids can associate with each other and with other types of molecules via specific intermolecular interactions

Molecular shape, Ionic bonds, Hydrogen bonds and Van der Waal’s interactions are important to determine strength and specificity of interactions

4 Fig. 2.17: Important Concept The function of a macromolecule is determined by its Molecular Shape (conformation) & Composition Macromolecules such as proteins work by interacting with other molecules. These interactions depend on the molecules having complementary shapes that fit together (like a lock and key)

Chapter 5: Biological Building Block Molecules (Monomers) and Macromolecules

Complex Polymer Monomer Simple Polymer (Macromolecule) Monosaccharide Polysaccharide Oligosaccharide (Simple Sugar) (Complex Carbohydrate ) Nucleotide Oligonucleotide Nucleic Acid Polypeptide Amino Acid Peptide Protein

5 Carbohydrates: Contain Carbon, Hydrogen and Oxygen in the ratio CH2O Monomers: The simplest Carbohydrates are the Simple Sugars, these are classified by: O Type of Carbonyl group  Ketone  Ketose R-C-R O Aldehyde  Aldose or by R-C-H Number of Carbon atoms: 3 C’s  Triose 4 C’s  Tetrose 5 C’s  Pentose 6 C’s  Hexose

Note: suffix …ose indicates a sugar

Trioses Aldose Ketose

All sugars, except Di-hydroxy acetone, can have D or L optical isomers, although only the D isomers exist naturally.

L-Glyceraldehyde D-Glyceraldehyde

6 Common Simple Sugars

Trioses

Pentoses

Hexoses

Fig. 5.4a: Linear and ring forms of glucose Pentoses and Hexoses form ring structures in water when one of the –OH groups forms a bond to the carbonyl group

Linear and 2 forms, β and α ring forms

7 Figure 5.5a: Disaccharides

1–4 glycosidic linkage

Glucose Glucose Maltose

Disaccharides contain two simple sugars joined by a Glycosidic Bond Common Disaccharides

Malt Sugar Milk Sugar Table Sugar Glucose-Glucose Galactose-Glucose Glucose-Fructose

Polysaccharides (Glycans):

Starch and Glycogen: Fuel storage polysaccharides

α (14) Glycosidic Bond

Cellulose: Structural polysaccharide

β (14) Glycosidic Bond

8 FLEig 5-6. 5.6: Food Storage Polysaccharides - Starch and Glycogen

Chloroplast Starch Mitochondria Glycogen granules

0.5 µm

1 µm

Amylose Amylopectin Glycogen

Starch: a plant polysaccharide Glycogen: an animal polysaccharide

LE 5-8 Fig. 5.8: Structural Polysaccharides - Cellulose

Cellulose microfibrils in a plant cell wall Cell walls Microfibril

0.5 µm

Plant cells

Cellulose molecules

β Glucose monomer

9 Structural Polysaccharides - Chitin

β (14) Glycosidic Bond Chitin forms the hard exterior exoskeleton of insects It is also used to make biodegradable surgical threads

Nucleotides / Nucleic Acids

10 Nucleotides: Adenine consists of three components: •Nitrogenous base, Adenine in this example Phosphate •A sugar: ribose or 2’-deoxyribose •Phosphate

N-Glycosidic Bond

Adenosine 5’-monophosphate (AMP) Phosphoester Bond

RNA DNA

Fig. 5.26a: The components of Nucleic Acids 5′ end

Nucleoside Nitrogenous base Phosphodiester Bond

Phosphate group Pentose sugar

Nucleotide

3′ end Polynucleotide, or Nucleic Acid

11 Fig. 5.26b: Nucleoside Components

Nitrogenous bases Pyrimidines

Cytosine Thymine (in DNA) Uracil (in RNA) C T U

Purines

Adenine Guanine A G

Pentose sugars

Deoxyribose (in DNA) Ribose (in RNA)

Nucleoside components

Fig. 5.27: The DNA double helix and its replication.

5′ end 3′ end

Sugar-phosphate backbone

Base pair (joined by hydrogen bonding)

Old strands

Nucleotide about to be added to a new strand

5′ end

New strands

3′ end 5′ end

5′ end 3′ end

12 Lipids

Lipids are a diverse group of molecules which are primarily water-insoluble and include:

Fats triglycerides Oils Waxes Phospholipids Biological Steroids Membranes Carotenoids

Fatty acids are the building blocks of lipids

Fatty Acids

Saturated fatty acids: Unsaturated fatty acids: No double bonds between One or more double bonds adjacent carbon atoms between adjacent carbon atoms

Acyl chain (16 – 18 carbons)

Straight Bent (kinked) conformation conformation

13 Fig 5.11 & 5.12: Triglycerides

Triglycerides consist of 3 fatty acids bonded to the three hydroxyl (-O-H) groups of a molecule of glycerol (ester bonds) Fats = triglycerides from animals with mostly saturated fatty acids

(condensation reaction)

Oils = triglycerides from Acyl chains can be saturated plants with mostly unsaturated or unsaturated fatty acids

Fig 5.13: Phospholipids

Hydrophilic head

2 Hydrophobic tails

Phospholipds are amphipathic molecules (contain both hydrophilic and hydrophobic parts)

14 Fig 5.14 / 7.2: Phospholipids Assemble to Form Membrane Bilayers

Fig 7.2

Phospholipid bilayers form impermeable membranes that enclose and compartmentalize cells

Steroids are lipid molecules (water insoluble) based on a hydrocarbon structure with four fused rings

Cholesterol is the most common steroid and is found in membranes

Cortisol, Estrogen and Testosterone are steroid The Polar -OH group makes hormones this molecule amphipathic