Sugar Alcohols and Reactions Quiz

Carbohydrates

• Carbohydrates are composed of carbon, hydrogen, and oxygen, with the general formula Cn(H₂O)n.
• Many carbohydrates are found in foods, including polysaccharides (starches in bread/pasta), disaccharides (sucrose/table sugar), and monosaccharides (glucose, fructose, lactose).
• Photosynthesis uses energy from the sun to create glucose from carbon dioxide and water.
• Respiration breaks down glucose to release energy for cellular processes, producing carbon dioxide and water.
• Carbohydrates are essential in the carbon cycle.

Types of Carbohydrates

• Monosaccharides are the simplest carbohydrates, cannot be further broken down, examples include glucose, fructose, and galactose.
• Disaccharides are composed of two monosaccharides joined together, which can be split by hydrolysis to yield their component monosaccharides, e.g., sucrose (glucose + fructose) or lactose (glucose + galactose).
• Polysaccharides are polymers of many monosaccharides, examples include starch (amylose and amylopectin), glycogen, and cellulose.

Chiral Molecules

• A chiral carbon atom is bonded to four different atoms or groups.
• Stereoisomers are molecules with the same molecular formula but different three-dimensional arrangement of atoms.
• Enantiomers are stereoisomers that are non-superimposable mirror images.
• Achiral objects have superimposable mirror images.

Monosaccharides

• Contain several hydroxy! groups attached to a three to seven carbon chain.
• First carbon in the chain is an aldehyde (aldose) or a ketone (ketose).
• Classified by the number of carbon atoms; trioses, tetroses, pentoses, hexoses.

Chiral Carbons

• A chiral carbon atom has four different groups or atoms attached. This means that the mirror image cannot be superimposed on the original.
• The resulting structures are stereoisomers.
• If stereoisomers cannot be superimposed on each other, then they are enantiomers.

Fischer Projections

• A system for depicting the three-dimensional structures of isomers.
• Shows the arrangement of atoms around chiral carbons.

Fischer Projections of Monosaccharides

• The most common monosaccharides contain five or six carbon atoms, which have several chiral carbons.
• Their Fischer projections can be drawn as a mirror image, which can produce enantiomers.

Important Monosaccharides

• D-glucose, D-galactose, D-fructose are common hexoses (six-carbon sugars).

Disaccharides

• Formed when two monosaccharides combine through a dehydration reaction, resulting in the loss of a water molecule, producing a glycosidic bond.
• Examples include maltose (glucose + glucose), lactose (glucose + galactose), and sucrose (glucose + fructose).
• Maltose is obtained from starch and is found in germinating grains.
• Lactose is the sugar in milk and milk products.
• Sucrose is table sugar and is a non-reducing sugar.
• If a person cannot digest lactose, then it is undigested in the colon and can cause bloating.

Polysaccharides

• Large polymers formed by many monosaccharides linked together.
• Important polysaccharides are starch (amylose and amylopectin), glycogen (animal starch), and cellulose.
• Starch is found in plants, glycogen in animals, and cellulose in plants for structural support.
• Starches are hydrolyzed into smaller saccharides like detrins and then to maltose and finally glucose by amylases and maltases (saliva and intestinal ezyemes).

Lipids

• A family of biomolecules that are soluble in organic solvents but not water.
• Types of lipids include waxes, triacylglycerols (glycerols esterified with fatty acids), glycerophospholipids, sphingolipids, and steroids.

Fatty acids

• Long, unbranched hydrocarbon chains with a carboxyl group at one end.
• Saturated fatty acids contain only single carbon-carbon bonds, while unsaturated fatty acids contain one or more double bonds, which create kinks in the chain.

Cis and Trans Isomers

• Cis isomers have the same groups on the same side of the double bond, while trans isomers have the groups on opposite sides.
• The cis form is more common and often found in natural unsaturated fatty acids.

Prostaglandins

• Hormone-like substances that influence various bodily processes.
• Derived from arachidonic acid, a 20-carbon polyunsaturated fatty acid.
• Different prostaglandins have different substituents.

Waxes

• Esters of long-chain fatty acids and long-chain alcohols.

Triacylglycerols

• Triesters of glycerol combined with three fatty acids.
• Stored in animals as a major energy source.

Phospholipids

• Glycerophospholipids and sphingomyelins
• Glycerol backbone with two fatty acids esterified; the third OH group reacted with a phosphoric acid, which is further esterified with an alcohol.
• Sphingosine replaces glycerol in sphingomyelins.

Amino Alcohols

• Important components in glycerophospholipids and other lipids.
• Examples include choline, serine, and ethanolamine
• Usually ionized at a pH of 7.4

Steroids

• Cholesterol, bile salts, and steroid hormones
• Four fused carbon rings as a core structure (steroid nucleus).

Lipoproteins

• Complexes of lipids, phospholipids, and proteins.
• Transport lipids in the blood stream, differing by density and lipid composition.
• Examples are chylomicrons, VLDLs (very-low-density lipoproteins), LDLs (low-density lipoproteins), and HDLs (high density lipoproteins).

Proteins and Amino Acids

• Large polymers of amino acids linked together by peptide bonds.
• 20 amino acids commonly found in biological proteins.
• Each amino acid has a central carbon atom bonded to NH₃+, COO⁻, H, and an R group.

Protein Structure

• Primary: amino acid sequence
• Secondary: α-helix, β-sheets, stabilized by H-bonds.
• Tertiary: 3D structure stabilized by interactions between R groups (hydrogen bonds, salt bridges, hydrophobic interactions, disulfide bonds).
• Quaternary: multiple polypeptide chains come together.

Enzymes

• Biological catalysts, usually proteins that speed up chemical reactions in the body by lowering activation energy.
• Enzyme-substrate complexes form, with specific interactions at the active site, leading to a catalyzed reaction.

Inhibition of Enzymes

• Competitive inhibitors compete with substrates for the active site.
• Noncompetitive inhibitors bind at a different site, changing enzyme shape and decreasing activity.
• Irreversible inhibitors bind permanently and cause permanent loss of enzymatic function.

Nucleic Acids

• DNA and RNA
• Composed of nucleotides that are composed of a sugar, a phosphate group, and a nitrogenous base (adenine, guanine, cytosine, thymine, and uracil..).
• DNA is a double helix; RNA is usually single-stranded.
• The genes' information is transcribed into RNA, which is translated into proteins.

Nucleic Acid Base Pairs

• Complementary bases pair up to form hydrogen bonds: adenine with thymine or uracil, and cytosine with guanine.

DNA Replication

• DNA is replicated by unwinding the double helix and using each strand as a template to synthesize a complementary strand. DNA polymerase is an enzyme crucial to this process.

RNA and Transcription

• RNA molecules are involved in protein synthesis.
• Transcription is the process of copying a segment of DNA (gene) into an mRNA molecule.
• mRNA carries the genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm.

The Genetic Code and Protein Synthesis

• The genetic code consists of three-base codons on mRNA which specify an amino acid sequence.
• Translation is the process where codons are read by ribosomes, and matching tRNA molecules bring in the corresponding amino acids to form a polypeptide chain.
• mRNA codes for the amino acid sequence to make a functional protein which is then folded, via amino acids bonds to make a three-dimentional shape

Mutations

• A mutation is a change in the DNA sequence.
• There are different types of mutations which include point mutations (substitutions), insertions, and deletions.

Important Note

This is a comprehensive summary of the text provided. There are additional figures, examples, and details in the original source material which are not included in these shortened notes. Visuals and diagrams are essential to a thorough understanding of these topics.

Test your knowledge on sugar alcohols, their formation, and reactions involving disaccharides and carboxylic acids. This quiz covers topics such as the formation of maltose, lactose, and esters. Dive into the chemical processes and facts about these important compounds.