Chapter 3: The Chemical Building Blocks of Life Flashcards
What are the four types of organic molecules?
carbohydrates, lipids, proteins, nucleic acids
How many atoms can carbon bond to? What kinds of bonds can it form?
4, single, double, triple, quadruple
How many valence electrons does carbon have?
4
What is the backbone of biological molecules?
carbon
Hydrocarbons
molecules consisting of ONLY carbon and hydrogen
Where are many hydrocarbons found?
in many of a cell’s organic molecules
Isomers
molecules with the same molecular formula but different structures and properties
What are the three types of isomers?
- structural
- geometric
- enantiomers
Structural isomers
- isomers with differences in actual structure of their carbon skeletons
- ex) glucose and fructose
Geometric (stereoisomers) isomers
have same carbon skeleton, but differ in how the groups are attached to the skeleton
Enantiomers
- mirror images of each other
- important in pharmaceutical industry
What are functional groups and their purpose?
- parts of molecule involved in chemical reactions
- chemically reactive groups of atoms within an organic molecule
- give organic molecules distinct chemical properties
What are the 6 functional groups important to life?
- hydroxyl
- carbonyl
- carboxyl
- amino
- sulfhydryl
- phosphate
Hydroxyl group
hydrogen atom bonded to oxygen atom; this is bonded to the carbon skeleton
Carbonyl group
carbon atom double bonded to oxygen atom
Carboxyl group
oxygen atom is double bonded to a carbon atom, which is also bonded to a hydroxyl group (COOH)
Amino group
nitrogen bonded to two hydrogen atoms and to the carbon skeleton
Sulfhydryl group
sulfur atom bonded to hydrogen atom
Phosphate group
phosphorus atom bonded to four oxygen atoms; one oxygen bonded to carbon skeleton
Ketones
carbonyl group is within carbon skeleton
Aldehydes
carbonyl group at the end of the carbon skeleton
What type of bonds are the subunits of macromolecules joined by?
covalent bonds
Dehydration Synthesis
- one molecule of water (H2O) is removed as subunits are linked with a bond
- water is produced
- anabolic (build up)
- requires input of energy
- enzymes carry out the breaking of bonds
Hydrolysis
- molecule can be broken down into subunits as water is added
- water is needed
- catabolic
- energy released
- enzymes needed
Monomers
simplest unit of macromolecules
Polymer
large molecule made of repeating monomers
What are carbohydrates?
“sugars” and “starches”
What elements are found in carbs?
C, H, O
Ratio of C:H:O in carbs
1:2:1
Function of carbs
- short term energy storage
- structure
Examples of carbohydrate isomers
glucose, fructose, galactose
What kind of isomers are glucose and fructose
structural isomers, double bonded O is attached to diff carbons
What kind of isomers are glucose and galactose
stereoisomers, diff orientation of -OH groups
What are the most famous monosaccharides?
hexose sugars
How are disaccharides formed
2 monosaccharides connected by a covalent bond
Glucose + Glucose
Maltose
Glucose + Fructose
Sucrose
Glucose + Galactose
Lactose
What are big polymers of sugar called?
Polysaccharides
Function of glucose polymers
- energy storage
- structural support
Amylose (starch)
- used for energy storage in plants
- alpha linked
Glycogen
used for energy storage in animals, stored in liver and muscles
Cellulose
- major component of plant-like cell walls
- beta linked
Pectin
branched chains with short linear amylose branches found in plants
Why is cellulose difficult to digets?
orientation of glucose subunits (CH2OH) are on opposite sides, so it is hard to break the bonds
Chitin
- structural support in fungi cell walls
- exoskeleton of insects
- dissolving stiches
- modified polysaccharide
How do herbivores digest cellulose?
cows have bacteria that can break down cellulose
Peptidoglycan
- in bacterial cell walls
- modified peptidoglycan
What are the 3 ways that carbohydrates are used in organisms?
1.) kept as glucose/immediate energy
2.) converted to transport disaccharides
3.) converted to starch, glycogen, or fat, and used in the future
What are common lipids?
fats, oils, waxes
What elements are found in lipids?
C, H, O
Ratio of H:O in lipids
greater than a 2:1 ratio