Molecular and Cellular Exam 1 Flashcards
What is a hydroxyl group?
A standard molecular bonded to oxygen.
The oxygen bonded to hydrogen
Polar
What is a methyl group?
A standard molecule bonded to CH3
Nonpolar
What is a carbonyl group?
Two standard molecules bonded to carbon
Carbon double bonded to oxygen
Polar
What is a carboxyl group?
A standard molecule bonded to carbon
Carbon bounded to OH and double bounded to oxygen
Charged and ionizes to release H+. Acidic
What is an amino group?
A standard molecule bonded to nitrogen
Nitrogen bonded to two hydrogen atoms
Charged, accepts H+ to create ammonia (NH3+). Basic
What is a sulfhydryl group?
A standard molecule bonded to sulfur
Sulfur bonding to hydrogen
Polar
What is a phosphate group?
A standard molecule bonded to phosphate
Phosphate bonded to oxygen, two OH and double bonded to one oxygen
Charged, ionizes to release H+. Acidic
What is the unique property of liquid water?
Hydrogen bonds are constantly made, broken and remade
What is the unique property of gaseous water?
Water is heated the increased kinetic energy of water causes hydrogen bonds to break and water molecules escape into air as gas
What is the unique property of solid water?
Temperature is lowered and a crystalline structure is maintained
Why does solid water float on liquid water?
Hydrogen bonding in water causes solids to be less dense than liquids
What is the specific heat capacity of water?
Specific heat capacity refers to the amount of heat one gram of a substance must absorb in order to raise its temperature one degree Celsius
What is the heat of vaporization in regards to water?
The amount of energy required to change one gram of a liquid substance to gas
What is cohesion in water?
Water molecules at the liquid-gas interface stick together due to hydrogen bonding
What is surface tension in water?
Capacity of a substance to withstand being ruptured when placed under tension or stress
How does capillary action work?
Capillary action in a glass tube is caused by the adhesive forces exerted by the internal surface of the glass exceeding the cohesive forces between the water molecules themselves.
What is adhesion?
It is an attraction between water molecules and other molecules
What are the four macromolecules?
- Lipids
- Carbohydrates
- Proteins
- Amino Acids
What element is essential to life and macromolecules?
Carbon
Why is carbon unique?
It can form covalent bonds with up to four different atoms
This allows it to serve as the “backbone” for the macromolecules
Each carbon has four electrons in the outer shell
It forms four covalent bonds to “fill” the outer shell
This allows it to achieve the “octet rule”
What is CH4?
Methane
What affects the function of molecules?
The shape or the geometry!
What are hydrocarbon rings?
Molecules with 5-6 carbon atoms that are single or double bonded to each other that form a ring
**Nitrogen can replace carbon
What are isomers?
Molecules that have the same chemical formula but differ in placement/arrangement of atoms or types of bonds between atoms
What are the three types of isomers?
Structural
Geometric
Enantiomers
What are structural isomers?
They are isomers that have a different covalent arrangement of atoms.
What are geometric isomers?
They are isomers that have a different arrangement of atoms around a double bond
What are enantiomers?
They are molecules that share chemical formula and bonds but differ in 3D placement of atoms; mirror images
What are unsaturated hydrocarbons?
They are fatty acids made up of carbons with at least one double bond
What are saturated hydrocarbons?
They are fatty acids made up of carbons with no double bonds
What is a trans fatty acid?
A fatty acid with carbons are on opposite sides of double bond so a molecule chain remains straight
What is a cis fatty acid?
A fatty acid with carbons on the same side of a double bond so a molecule chain is bent
What molecules can dissolve in water?
Ions and polar molecules can dissolve in water
What is a hydrogen bond?
Interaction between the δ+ of hydrogen and the δ- of a more electronegative atom on another molecule – often occurs between water molecules
What are van der Waals interactions?
Weak attractions or interactions between two or more molecules (in close proximity) due to changes in electron density
What are ionic bonds?
Metals lose electrons and nonmetals gain electrons to achieve an octet when bonding
What is a chemical bond?
The attractive force that links atoms together to form molecules
What is a covalent bond?
Two or more atoms may bond with each other to form a molecule by sharing electrons
What is a polar covalent bond?
Electrons are unequally shared by the atoms and attracted more to one nucleus than the other
What is electronegativity?
The ability to attract and gain electrons
Four major macromolecules
Lipids
Carbohydrates
Proteins
Nucleic acids
Macromolecules consisting of individual subunits
Monomers
Monomers linked together by covalent bonds
Polymers
Monosaccharides
Simple sugars and the most basic units from which all carbohydrates are built
Three requirements of a monosaccharide
-3-7 carbons
-End with the suffix –ose
-Contain a carbonyl group C=O
Five types of monosaccharides
-Aldoses
-Ketoses
-Trioses
-Pentoses
-Hexoses
Aldoses
Carbonyl group at the end of the carbon chain
Ketoses
Carbonyl group in the middle of the carbon chain
Trioses
Three carbons
Pentoses
Five carbons
Hexoses
Six carbons
Dehydration synthesis
Two monosaccharides bonded together by a covalent bond and releasing a water molecule
Hydrolysis (Dehydration reaction)
Water reacts with polymers to break them down into individual monomers
Enzymes
Biological molecules that speed up or catalyze reactions like hydrolysis or dehydration synthesis
Monosaccharides exist in this form in aqueous solutions
5-6 carbon ring between ring and linear in equilibrium, creating alpha and beta sides
Glycosidic bond
The bond between two monosaccharide monomers forming a covalent glycosidic linkage
Polysaccharides
A long chain of monomers bonded by glycosidic linkages
Potential characteristics of polysaccharides
-May be branched or unbranched
-May consist of multiple types of monosaccharides
-Molecular weight could be > 10,000 daltons
-May be distinguished by the formation of the bonds
Cellulose
A polysaccharide found in the cell wall of plants and made of unbranched chains of glucose monomers
Lipids
-Diverse group of non-polar hydrocarbons which are hydrophobic
-Includes fats and oils
Two components of fats
- Glycerol
- Fatty acids
Triacylglycerol and bond type
Formed by bonding three fatty acids to a glycerol backbone via an ester linkage
Three water molecules are released
Stearic acid
A common saturated fatty acid (solids at room temperature like meat, butter, etc.)
Oleic acid
A common unsaturated fatty acid (liquid at room temperature like oils)
Phospholipids
Two fatty acids and a phosphate group bonded to a bonded to a glycerol backbone
The structure of a phospholipid
Two layers of phospholipids with the phosphate hydrophilic heads protecting the fatty acid hydrophobic tails
A common function of phospholipids
They contribute to the dynamic nature of plasma membranes
The macromolecule category of steroids
Lipids
The main features of steroids
- Hydrophobic
- Insoluble in water
- Typically a ring shaped molecule with four linked carbon rings with unique short tails
The most common steriod
Cholesterol
Amino acids
Monomers that make up proteins
The 5 fundamental features of amino acids
- Central carbon atom
- Amino group (-NH2)
- Carboxyl group (-COOH)
- Hydrogen
- Side chain
How are amino acids commonly written?
Amino acids are represented by a single upper case letter or three letters