SBI4U Test 1 Flashcards
Name the 6 functional groups
amino, hydroxyl, carboxyl, carbonyl (aldehydes and ketone) sulfhydryl, phosphate.
What functional group is this?
amino
What functional group is this?
hydroxyl
What functional group is this?
carboxyl
What functional group is this?
carbonyl ketone
What functional group is this?
carbonyl aldehyde
What functional group is this?
sulfhydryl
What functional group is this?
phosphate
What are isomers? Name the three types.
These are organic compounds with the same molecular formula, but different molecular structure. These include structural, geometric and optical isomers.
What are structural isomers?
These are isomers which have the same atoms but are bonded together differently.
What are geometric isomers?
These are isomers where there is usually a variation around a double bond or ring structure. They have different physical properties but the same chemical properties.
Optical Isomers
These are molecules which are “mirror images” of each other. They have the same chemical and physical properties but usually one form is biologically inactive.
What is the word equation for the synthesis of a maltose molecule?
αglucose + αglocuse –maltase–> maltose + water
What is the word equation for the synthesis of a lipid molecule?
glycerol + 3fatty acid –lipase—> lipid + 3water
What is the word equation for the synthesis of a dipeptide?
amino acid 1 + amino acid 2 –proteinase–> dipeptide + water
What are saturated fats vs. unsaturated fats? Compare 3 components of each.
Saturated
- no carbon double bond
- solid at room temperature
- found in animal tissue
Unsaturated
- contains double bonds between carbon atoms -> prevents molecules from packing close enough to solidify
- can hold more hydrogen atoms
- liquid at room temperature
What are cis vs. trans fatty acids?
Trans - Elaidic acid is a trans unsaturated fatty acid often found in partially hydrogenated vegetable oils.
Cis - Oleic acid is a cis unsaturated fatty acid that comprises 55-80% of olive oil.
What are lipids and phospholipids?
Phospholipids are a type of lipids.
- Lipids are hydrophobic, while phospholipids are amphiphilic - tail is hydrophobic (nonpolar) and head is hydrophilic (polar)
- Lipids contain C, H, and O while phospholipids contain P also
- Lipids are generally composed of glycerol and 3 fatty acids while phospolipids are usually made of only 2 fatty acids and a phosphate group
Distinguish between essential and non-essential amino acids.
Essential amino acids are those which are not synthesized by the body or cannot be sufficiently made by the body. The must be found in the diet. There are 8 essential amino acids for adults and 10 for infants.
Non-essential amino acids are those that the body synthesizes sufficiently.
What are the four levels of protein organization? Name them.
Primary structure, secondary structure, tertiary structure, and quaternary structure.
What is primary structure (the first level of protein structure)?
Unique sequence of amino acids in a polypeptide
What is secondary structure (the second level of protein structure)?
Bending of the polypeptide (primary structure) due to hydrogen bonding between functional groups. Forms α-helix (a coil) and ß-sheets (like an accordion fold map)
What is tertiary structure (third level of protein structure)?
The shape of polypeptide due to interactions of R-groups. Interaction types include: disulfide bridges (form between sulfhydryl groups; very stable), ionic bonds, and hydrogen bonds.
What is quaternary structure (fourth level of protein organization)?
Relationship between several polypeptide chains. Forms globular shapes. Not all proteins have this level of organization, e.g. hemoglobin
How do you test for lipids present in food?
Add Sudan IV (6 drops to 5 mL). Result should turn red.
How do you test for glucose present in food?
Benedict’s solution (5 drops for 5 mL) is added and placed in a hot water bath for 5 min. Results will turn yellow orange (light green - low, yellow orange - medium, brown red - high)
How to do you test for the presence of protein in food?
Biuret reagent (10 drops for 5 mL) will turn purple if protein is presenst.
How do you test for the presence of polysaccharides?
Iodine solution (5 drops for 5 mL) turns dark blue/black.
What five things is the cell membrane mainly composed of?
Phospholipid (bilayer), cholesterol, peripheral protein, integral protein (transport protein), and carbohydrate chain markers.
What is the purpose of cholesterol molecules in the cell membrane?
To prevent the phospholipids from packing too tightly and allows the membrane to remain fluid.
What is the name of the model for the cell membrane? Who proposed it and when?
The Fluid Mosaic Model was proposed in 1972 by S. Singer and G. Nicolson
What is dehydration synthesis?
Components of a water molecule are removed to bond two molecules together. Interaction occurs between functional groups.
What are the five key properties of water?
- It is a universal solvent.
- Water expands upon freezing (makes ice float in water)
- High specific heat (gradual change in temperature when water is heated or cooled)
- High Heat of Vapourization (requires a lot of energy to turn from liquid to gas due to breaking of hydrogen forces) - allows us to sweat
- Adhesion & Cohesion (attraction of molecules to each other) - surface tension, lets plants pull water up from roots.
cohesion = same types of molecules
adhesion = different types of molecules
What are the three functions of carbohydrates?
- Energy
- Storage (as glycogen, or converted to fat)
- Fibre or roughage (prevention of constipation or intestinal cancer)
What are the units, number of units, structure and digestive enzyme for amylose?
Unit: α-glucose
of units: 60-300
Structure: straight chain
Digestive enzyme: amylase
What are the units, number of units, structure, and digestive enzyme for glycogen?
Unit: α-glucose
of units: 300-6000
Structure: branched chain
Digestive enzyme: amylase
What are the units, number of units, structure, and digestive enzyme for cellulose?
Unit: ß-glucose
of units: 1800-3000
Structure: straight chain
Digestive enzyme: cellulase
***Body can’t digest cellulose
What are the 5 functions of lipids?
- Concentrated energy
- Storage of energy
- Part of plasma membrane- phospholipids, cholesterol
- Solvent for vitamins (A, D, E, K)
- Protection/insulation (cushions organs)
What are the 5 functions of proteins?
- Structural - bones & muscle
- Biological catalyst - enzymes
- Chemical messengers - hormones, neurotransmitters
- Transport - hemoglobin
- Energy
