Ch.3 - The Chemistry of Organic Molecules

organic chemistry

the chemistry of living things. C-H bonds

4 types of organic molecules

protein, nucleic acid, carbohydrate, fat

3 properties of carbon that allow for organic molecules

• very stable → allows formation of long carbon chains

• can form ring structure when placed in water environment

• can form double bonds with itself or other atoms

functional group

specific combination of bonded atoms that always read the same way regardless of the carbon skeleton it is attached to

which biomolecule has both carboxyl and amino groups present in it

amino acids

what would it be useful to know which functional groups are present in a molecule?

they determine a molecules properties and reactivity = predict chemical behavior

isomer

organic molecules that have identical molecular formulas but have different arrangements of atoms

monomers

small molecules that are building blocks for larger molecules

polymers

long chains of monomers

polymerization

the process of joining monomers to form polymers

dehydration synthesis

aka “condensation reactions”. a chemical reaction that forms a larger molecule from two smaller molecules, called monomers, by removing a molecule of water

anabolic reaction

putting molecules together, requires an input of energy

hydrolysis

“water breaking”

catabolic reaction

breaks down complex molecules into simpler ones, releasing energy that the body uses for cellular processes

what are the monomers called that get glued together to build a carb?

monosaccharides

what are the monomers called that get glued together to build a protein?

amino acids

molecular formula for glucose

C₆H₁₂O₆

monosaccharides

simple sugars, smallest type of carb, used for immediate energy (ex. glucose, fructose, galactose)

disaccharides

two monosaccharides bonded together, used to transport sugars (ex. maltose, sucrose, lactose)

a disaccharide is formed using what type of chemical reaction?

dehydration synthesis

polysaccharides

carb made up of many sugars (ex. starch, glycogen, cellulose, chitin)

lipids

hydrophobic (not water soluble), non-polar

fats

found in animals, functions as long-term energy and insulation

oils

found in plants and seeds, functions as long-term energy storage

phospholipids

component of plasma membrane

steroids

component of plasma membrane (cholesterol) and sex hormones

waxes

protection, prevention of water loss (ex. beeswax, earwax)

what two components make up fats and oils?

glycerol and fatty acids

contrast unsaturated and saturated fatty acids

saturated fatty acids lack double bonds between carbon atoms and contain as many hydrogen they can hold. unsaturated fatty acids have double bonds in the carbon chain, which reduces the number of bonded hydrogen atoms

contrast the structure of a phospholipid and a fat

phospholipids have a hydrophilic phosphate head and 2 hydrophobic fatty acid tails, making it amphipathic (hydrophilic & hydrophobic). Fats have 3 hydrophobic fatty acid tails & a glycerol backbone, making them entirely hydrophobic.

describe the structure of a steroid

they have a fused system of four carbon rings

3 functions/characteristics of cholesterol

1. provides physical stability

2. precursor of several other steroids

3. contribute to cardiovascular disorders → accumulate in blood vessels

2 functions of waxes

1. in many animals → skin and fur maintenance

2. in humans → earwax, which protects eardrum

6 functions of proteins in cells

1. metabolism (enzymes)

2. support/structure

3. transport

4. defense (antigens/antibodies)

5. regulation (hormones)

6. motion

specific name of the chemical bonds that holds together amino acids

peptide bond

polypeptide

a chain of many amino acids joined by peptide bonds

primary structure

• amino acid arrangement/sequence

• determined by genes in DNA

• results in chains of amino acids held together by peptide bonds

secondary structure

• localized folding of polypeptide

• determined by hydrogen bonds between polar amino acids

• results in alpha helix or beta sheet

tertiary structure

• overall folding of polypeptide

• determined by non-polar side group “hiding” from water

• results in 3-D “knotted” shape

quaternary structure

• interaction of 2+ folded peptides

• determined by bonding between several polypeptides

• results in function, globular proteins

denatured protein

when a protein loses its natural shape and will most likely not be able to function properly

chaperone proteins

help new proteins fold into their normal shape

TSE

• transmissible spongiform encephalopathies

• group of rare, fatal neurodegenerative diseases that affect both humans and animals

• caused by prions

prions

• a misfolded protein

• infectious

• can cause normal proteins to misfold

nucleic acids are polymers of what monomer?

nucleotides

3 parts of a nucleotide

1. pentose sugar

2. phosphate

3. nitrogen base

contrast structure of prurine and pyrimidine

purines have larger, double-ring structures containing 4 nitrogen atoms while pyrimidines have smaller, single-ring structures with two nitrogen atoms

adenine pairs with?

thymine

guanine pairs with?

cytosine

DNA

• deoxyribonucleic acid

• forms a helix

• used 4 bases → a, t, g, c

• uses deoxyribose sugar

• double-stranded

• contains genes → instructions for building proteins

RNA

• ribonucleic acid

• does not form a helix

• uses 4 bases → a, g, c, and uracil (u)

• single-stranded

• uses ribose sugar

• reads and follows instructions in genes, builds proteins

ATP

• adenosine triphosphate

• stores energy in P~P bonds

• releases energy when last P~P bond is broken

ADP

• adenosine diphosphate

• becomes ATP when energy and a phosphate are added

What type of bonds does carbon typically form to create biomolecules?

covalent

Which of the following are functional groups in organic biomolecules?

• Amino

• Carbonyl

• Phosphate

• Sulfhydryl

______ are small subunits, that when combined, form polymers.

monomers

What is the typical carbon-to-hydrogen-to-oxygen ratio of a carbohydrate?

1:2:1

Pentoses and hexoses are categories of carbohydrates called ________-.

monosaccharides

A combination of bonded atoms attached to an organic molecule that always reacts in the same way is known as a(n) ________ group.

functional

which type of reaction produces a disaccharide?

dehydration

Complex carbohydrates are often called _____

polysaccharides

Determine the type of polysaccharide found in each of these organisms:

• plant:

• crab:

• bacterium:

• plant: cellulose

• crab: chitin

• bacterium: peptidoglycan

Fatty acids and glycerol are the subunit molecules of ________

triglycerides

A molecule that contains a long hydrocarbon chain and ends with a (-COOH) carboxyl group is called a(n) ______

fatty acid

Cellulose, chitin, and peptidoglycan are all examples of ______ polysaccharides.

structural

Saturated fatty acid

Do not have double bonds between the carbon atoms in the chain

Unsaturated fatty acid

Have one or more double bonds between the carbon atoms in the chain

Select the polysaccharides that serve as structural molecules from the choices.

• Cellulose

• Chitin

Which feature of a lipid makes it insoluble in water?

Their hydrogens are bonded only to carbons making them nonpolar

The following carbon backbone would represent a(n) __________:

C-C-C-C-C-C=C-C=C-C-C=C-C-C-C

unsaturated fatty acid

The subunits of a triglyceride are

fatty acids and glycerol

Most of the fatty acids in cells contain an even number of carbons with ______ carbon atoms per molecule.

16 to 18

Which feature is used to distinguish between a saturated fatty acid and an unsaturated fatty acid?

Saturated fatty acids lack a double bond between the carbon atoms.

A 3-carbon carbohydrate that contains three (-OH) hydroxyl groups is called

glycerol

Why is there a kink in the tail of a phospholipid?

There is a double bond between two of the carbon atoms.

a molecule that contains a long hydrocarbon chain and ends with a (-COOH) carboxyl group is called a(n)

nucleic acid

Which type of lipid is composed of a long-chain fatty acid bonded to a long-chain alcohol, and therefore contains alcohol functional groups in its final structure?

waxes

Which is the main role of proteins in cells?

Structural and functional molecules.

Which of the following describes all enzymes?

they speed up chemical reactions in the cell.

Identify the functional group at the end of the hydrocarbon chain that makes up a fatty acid.

-COOH (carboxyl group)

Identify the structures that are composed of keratin and/or collagen.

• Hair

• Tendons

• Ligaments

Identify the features associated with waxes.

• Long-chain fatty acids

• alcohol functional groups

Proteins that increase the rate of chemical reactions in the cell are known as

enzymes

Proteins are polymers constructed from ______ monomers.

amino acid

Which type of lipid is composed of a long-chain fatty acid bonded to a long-chain alcohol, and therefore contains alcohol functional groups in its final structure?

waxes

A small polymer composed of two or more amino acids is called a ______.

peptide

A protein can have up to ______ levels of structure.

four

A linear sequence of amino acids constitutes the _________ structure of a protein.

primary

Select the ways in which a polypeptide can change into a secondary structure.

• The polypeptide coils

• The polypeptide folds

Multiple amino acids joined together to form a chain is called a ______.

polypeptide

Which type of proteins exhibit only helices or pleated sheet structures?

Fibrous proteins

Identify the functions of nucleic acids.

• Store information

• Conduct chemical reactions

What is the most common shape for a fibrous protein?

helices

A diverse type of nucleic acid that performs multiple functions is called ______.

RNA

A nucleic acid is best described as

a polymer of nucleotides.

Which group of biomolecules is RNA classified as?

nucleic acids