AP Biology Test - Organic Molecules (Chapter 5)
What do organic molecules always contain?
Carbon & Hydrogen
Define macromolecule
Very large molecules. Ex.DNA
Define monomer
A small molecules that joins to form a macromolecules
Define polymer
A large molecule formed by repeating subunits of smaller molecules
What is dehydration synthesis
A chemical reaction that produces larger molecules from smaller molecules that involves the removal of water
Define hydrolysis
A chemical reaction where chemical bonds are broken that involves the addition of water.
What are carbohydrates made up of
Carbon, hydrogen, and oxygen
What is the general formula for carbohydrates?
CH2O
What are the functions of carbohydrates?
1. Short term energy supply
2. Storage of energy
3.Structural material
4. Cell membrane markers
Define monosaccharides
Simple sugars consisting of one molecule unit.
What ending indicate sugars
"ose"
How may monosaccharides be grouped?
By how many carbon atoms they contain. Ex.Pentose - 5 carbon sugar, Hexose - 6 carbon sugar
Define disaccharides
A molecule formed from 2 monosaccharides by a dehydration synthesis reaction
What is a glycosidic linkage
A covalent bond formed between two monosaccharides by a dehydration reaction
What are monosachharides and disacchardies soluble in
Water
Define polysaccharides
A polymer of monosaccharides
What are three common polysaccharides found in living organisms?
Starch, glycogen, and cellulose
List the function, location, characteristics, and structure of starch
- Energy storage for plants
- Found in plants
- Fairly straight chains
- Few side branches off the main chain
List the function, location, characteristics, and structure of glycogen
- Energy storage for animals
- Found in animals
- Many branches and side chains in the molecule
List the function, location, characteristics, and structure of cellulose
- Structural materials for plants
- Not digestable by humans
- Found in plant cell walls as a structural component
- Made up of beta form of glucose
- Alternating position of the oxygen in the glycosidic linkage
List the function, location, characteristics, and structure of chitin
- Structural material in animals and fungi
- Found in exoskeletons of arthropod animals
- Similar to cellulose with beta linkages except that the glucose monomer has a nitrogen containing appendage
List the functions of lipids
1. Long term energy storage
2. Insulation or prevention of heat loss
3. Protective cushion/padding around major organs
4. Structural components of cell membranes
5. Chemical messengers (ex. hormones & steroids)
What is a neutral fat
Also known as a triacylglycerol or triglyceride, it is a lipid that has no groups that can ionize or become charged.
How are fats and oils formed?
They are formed when 1 molecule of glycerol reacts with 3 fatty acids
What is an ester linkage?
The bond that holds the glycerol and fatty acids together
How do you determine between saturated and unsaturated fats?
By the structure of the fatty acids within the fat molecule
Describe fattty acids
A hydrocarbon chain that ends with a carboxyl (acid) group. Most fatty acids in cells contain 16 or 18 carbon atoms per fatty acid molecule
List the properties of saturated fatty acids
- Are fatty acids without double bonds
- All the carbons are "saturated with all the hydrogen it can hold. Ex. Butter, lard
- Usually solid at room temperature
- Known to contribute to heart disease and strokes
List the properties of unsaturated fatty acids
- There are double bonds between carbon atoms
- Where there are cis double bonds, the carbon atoms have less than 2 hydrogen atoms
- If there is one double bond, it is a monounsaturated fat
- If there are more than one double bond, it is a polyunsaturated fat. Ex. Vegetable oil
- Usually liquid at room temperature
- Thought to be healthier for your heart
How do hydrogenated vegetable oils transform unsaturated fats to saturated fats?
By adding hydrogen. Some foods contain it to prevent them from becoming liquid form. Note: Saturated fatty acids only have single bonds & can pack tightly together. Unsaturated fatty acids have double bonds which causes the fatty acid to have a bent structure & prevents the molecules from packing tightly.
What is a phospholipid?
Similar to a fat molecule, but only has two fatty acids attached to glycerol.
Why are phospholipids important?
Are important components of the cell membrane in the form of a lipid bilayer
Explain the strucure of phospholipids
Are constructed like fats except 1 fatty acid is replaced by a phosphate group with a charged nitrogen attached. This part froms the polar "head" of the molecule while the rest of the molecule is nonpolar and resembles "tails"
Differentiate between hydrophobic & hydrophilic
Hydrophilic= Water fearing; not polar; no attraction to water :(; will group with other non-polar molecules.
Hydrophobic= Water loving; has attractions with water molecules :)
List the structure, functions & characteristics of steroids
- Their structure consists of 4 fused carbon rings
- They are derived from cholesterol
- Steroid function as chemical messengers and form many important hormones. Ex. Aldosterone - Regulates sodium levels in the blood, Estrogen & Testosterone - Sex hormones maintain female or male characteristics
Why is cholesterol essential?
Found as a component of the cell membrane. However, too much cholesterol can lead to arterial plaques. Cholesterol is found in animal products and not in plant foods
What are the main functions of proteins?
1. Proteins compose the physical structures of tissues and provide structural support. Ex.
- Keratin in nails & hair
- Collagen for connective tissues, ligaments, tendons, cartilage
- Actin & myosin in muscles, cilia, and flagella for movement
2. Proteins perform metabolic functions. Ex.
- Enzymes help speed up reactions
- Hormones act as chemical messengers
- Immunoglobulins or antibodies help fight pathogens in the immune system
Proteins are polymers or chains of what?
Amino acids. The sequence of amino acids gives the protein its characteristics
What are the 2 functional groups of amino acids?
The amino group and the carboxyl (acid) group. It also has a R group or remainder of the molecule which can vary from a single hydrogen to more complex ring-like structures. The R group side chains have chemical properties such as being hydrophobic, hydrophilic, acidic, or basic. There are 20 amino acids.
What are essential amino acids?
Our bodies can produce 12 amino acids. The other 8 we have to obtain from our food, these are called essential amino acids.
Define dipeptide
2 amino acids joined together
Define peptide bond
The bond that joins 2 amino acids
Define polypeptide
A series of amino acids connected together with peptide bonds; usually a very long chain
What is a chracteristic of peptide bonds
A peptide bond is polar and thus, there frequently is hydrogen bonding between different parts along a polypeptide and also between polypeptides and proteins. Several polypeptides can make up a protein.
What is a primary structure?
A polypeptide chain; a linear sequence of any amount and any combination of the 20 amino acids
What is a secondary structure?
A polypeptide chain orientation in space due to hydrogen bonding between different parts of the polypeptide chain; can be alpha helixes or beta pleated sheets
What is a tertiary structure?
The 3D shape of the protein due to bonding between R groups. The shape determines the function of the protein.
What is a quarternary structure?
Only found in proteins that consists of more than one polypeptide chain. It is a combination of many tertiary structures.
What happens in protein denaturing?
Happens when proteins are exposed to extreme heat or ph or salt concentrations. Bonds that hold the protein's specific shape are disrupted. Basically unravels the proteins.
DRAW the general structure of an amino acid
Hint: Carboxyl group + amino group + r group
What happens to misfoleded proteins?
An accumulation of misfolded proteins are associated with diseases such as cystic fibrosis, Alzheimer's, Parkinson's, and mad cow disease
What are the functions of nucleic acids?
1. Important for growth and reproduction of cells and organisms and control of protein synthesis
2. DNA is the genetic material that organisms inherit from their parents. It contains all the information that programs all the cell's activities. DNA is an example of nucleic acids.
3. RNA works in conjunction with DNA to direct protein synthesis. RNA is another example of nucleic acids
Define nucleotides
Monomers for nucleic acids
DRAW a nucleotide and label the molecule groups.
Hint: Phosphate + 5 carbon sugar + nitrogenous base (with one or two rings)
Differentiate between purines and pyrimidines
Pyrimidines:
- Six-membered ring of carbon and nitrogen
- Included thymine, cytosine, and uracil
Purines:
- Larger with 2 rings
- Includes adenine and guanine
Both DNA and RNA are-
Polymers of nucleotides that form from dehydration synthesis between nucleotides
List the complementary base pairings of nucleotides
Adenine pairs with thymine, guanine pairs with cytosine. Backbone is made up of the alternating sequence of sugar and phosphate
What is ATP?
Stands for adenosine triphosphate. It is a nucleotide that has the function of being the carrier of energy in cells. ATP consists of the sugar ribose, the base adenine, and the 3 phosphate groups
What are the unit molecule (building block) of protein? List one example of protein.
Amino acids; enzymes
What are the unit molecule (building block) of carbohydrates? List one example of carbohydrates.
Glucose (monosaccharide); glycogen
What are the unit molecule (building block) of lipids/neutral fats? List one example.
Fatty acid + glycerol; vegetable oils
Describe the structure of cellulose
Polymer of hexogonal glucose molecules
Diffferentiate between the structure of amylose (starch) and glycogen
Glycogen has more branching in its structure while amylose is more linear
What are peptide bonds for?
Holding together multiple amino acids (OH (of carboxyl) + H (of amino) --> C-N with H above nitrogen and double bond O above carbon)
Summarize the different types of proteins, their functions, and examples.
Enzymatic proteins:
- Selective acceleration of chemical reactions
Ex. Digestive enzymes catalyze the hydrolysis of bonds in food molucules
Storage proteins:
- Storage of amino acids
Ex. Plants have storage proteins in their seeds
Hormonal proteins:
- Coordination of an organism's activities
Ex. Insulin causes other tissues to take up glucose, thus regulating blood sugar concentration
Contractile & motor proteins:
- Movement
Ex. Cilia & flagella
Defensive proteins:
- Protection against disease
Ex. Antibodies
Transport proteins:
- Transport of substances
Ex. Hemoglobin transports oxygen from the lungs to other parts of the body
Receptor proteins:
- Response of cell to chemical stimuli
Ex. Receptors built into the membrane of a nerve cell detect signaling molecules released by other nerve cells
Structural proteins:
- Support
Ex. Keratin in hair, nails, horns, feathers, etc