Chemistry of Life Flashcards
bonding, functional groups, etc.
What is electronegativity? How can you tell the type of bond from it?
electronegativity is a measure of the strength with which an atom can attract electrons
how to tell the bond:
under 0.5 = covalent
between 0.5- 1.6 = polar covalent
above 1.6 = ionic
What are ionic bonds
bonds formed by the transfer of an electron from atom to atom
What are the two types of fatty acid molecules?
saturated fatty acid
unsaturated fatty acid
Whats a hydrolysis reaction?
a reaction to break apart the disaccharide with the addition of a single water molecule
simply: hydrolysis needs water to break apart the disaccharide
How to differentiate between alpha and beta glucose?
the 1st hydroxyl (OH) is at the bottom in alpha
the 1st hydroxyl is at the top in beta
What makes up a saturated fatty acid?
- single bonded chain (carbon)
- has max # of hydrogens
- saturated with H’s
- stable & doesn’t break easily
- SOLID @ ROOM TEMP
- the longer the chain, the less soluble it is
What are the properties of each functional group?
Hydroxyl
~ cmpds = alcohols
~ polar (electronegative oxygen atom draws electrons towards itself)
~ attracts water molecules & dissolves organic chemicals like sugar (hydrophilic)
~ molecules that contain this are soluble in water
Carbonyl
~ two types: ketones & aldehydes
~ polar as oxygen has a partially negative charge and carbon has a partially positive charge
~ hydrophilic
Carboxyl
~ cmpd = carboxylic acids
~ has acidic properties because of hydroxide ions
~ as the covalent bond between oxygen and hydrogen is so polar, hydrogen ions tend to disassociate
~ ionic form (cells) = carboxylate group
Amino
~ cmpd = Amine
~ acts as a base; picks up a proton from the surrounding solution
~ ionized with a charge of 1+ under cellular conditions
~ ex. as glycine has both an amine group and a carboxyl group, it is called an amino acid
Sulfhydryl
~ cmpd = thiols
~ two sulfhydryl groups can interact to help stabilize protein structure
Phosphate
~ cmpd = organic phosphates
~ makes the molecule its a part of an anion
~ can transfer energy between organic molecules
~ non polar & negatively charged
What are intramolecular bonds? What are the three types?
the bonds between atoms of the same molecule
three types:
~ pure covalent bonds
~ ionic bonds
~ polar covalent bonds
What is the acronym to draw beta glucose? how do you draw it?
B UDUD
(start from c1 to c4)
Whats a condensation/dehydration synthesis reaction?
a reaction where two monosaccharides join to form a disaccharide and a single water molecule is produced
simply: condensation produces water
Are lipids polar or non-polar? Why?
they are less polar as they have fewer hydroxyl and carboxyl groups making them hydrophobic (water-fearing)
What are the different polysaccharides (complex carbohydrates) and what are their functions?
- cellulose: plant structural support, fiber carbohydrate (cannot digest)
~ long straight chain
~ from beta glucose
~ linkages are beta 1, 4 - starch: short-term plant energy storage
~ fewer branches; slower to break down
~ linkage at a branch point is alpha 1,6
~ from alpha glucose - glycogen: short-term animal energy storage
~ many branches; fast to break down
~ branch point is alpha 1,6 - chitin: used by insects and crustaceans to form exoskeleton
~ has a nitrogen-containing functional group
what are polar covalent bonds
bonds formed when a pair of valence electrons is unequally between two atoms
What are the two types of unsaturated fatty acids? Describe each.
Cis:
- very bulky
- LIQUID AT ROOM TEMP
Trans:
- packed together well
- can be solid
- is unhealthy
What makes up an unsaturated fatty acid?
- one or more double bonds
- not saturated with H’s
- LIQUID @ ROOM TEMP
- 2 types: cis and trans
What is the formula for Glucose, Fructose, and Galactose?
C6H12O6
What type of linkage does alpha glucose + fructose form?
alpha 1,2 linkage
What is the acronym to draw alpha glucose? how do u draw it?
A DDUD
(start from c1 to c4)
U - up
D - down
Are carbohydrates polar or non polar? Why?
polar as they contain many hydroxyl groups which allow them to dissolve in water and participate in hydrogen bonding
What are inter-molecular bonds? What are the three types?
the bonds between atoms of different molecules
three types:
- hydrogen bonding (strongest)
- dipole-dipole interactions
- london dispersion force (weakest)
How do polar covalent bonds work
the atom with a larger nucleus attracts the electron more and has a slightly negative charge; the other atom is positive
What are the six functional groups
hydroxyl (-OH)
carbonyl (C=O)
carboxyl (C=O - OH)
amine (H- N - H)
phosphate (describe irl)
sulfhydryl (-SH)
what are pure (non-polar) covalent bonds
bonds formed by sharing a pair of valence electrons between two atoms
What are the functions of lipids?
- long-term energy storage
- steroid lipids act as hormones (chemical messengers)
- provides insulation (warmth)
- is a component of cell membranes
What are each of the functional groups found in?
hydroxyl = carbohydrates
carbonyl = lipids
carboxyl = proteins
amino = proteins
phosphate = DNA, ATP
Why is water a special molecule?
1) Hydrogen bonding
~ cohesion, adhesion, surface tension
~ water has a specific heat capacity as more energy is needed to break hydrogen bonds than other intermolecular bonds
2) Density
3) Polar nature of the bond
~ water allows polar molecules and ionic compounds to dissolve due to water’s polarity
4) Dissociation of intramolecular bonds
What is the structure for a glycerol molecule?
3 carbons with 3 hydroxyls (each carbon has 1 hydroxyl)
What are the two types of carbonyl groups
- Ketone: when the carbonyl structure is within the carbon skeleton (in the middle)
- Aldehyde: when the carbonyl structure is at the end of the carbon skeleton
Whats the bond between a glycerol molecule and fatty acids
ester linkages/bonds
Whats the difference between glucose and galactose (in terms of structure)?
the structure for galactose is the exact same as alpha glucose, however, the OH group on c4 is at the top for galactose instead of the bottom (as seen in alpha glucose)
Between Amylopectin and amylose, which is highly branched and which is not as branched?
Amylopectin is highly branched and amylose is not as branched
How does the structure of a phospholipid look?
it looks like the structure of a triglyceride [1 glycerol molecule (3 carbons with 3 hydroxyl) groups and 3 fatty acids], however, 1 fatty acid is replaced by a phosphate group
Describe the polarity of a phospholipid.
the head region of a phospholipid is polar and hydrophilic (likes water)
the tail region is non-polar and hydrophobic (avoids water)
What’s the chemical formula for a monosaccharide?
C6H1206
What is the structure of steroids? Give an example of a steroid and explain its importance?
four carbon-based rings attached
ex. cholesterol - critical in cell membrane structure & one of the chemicals used to make certain hormones like male and female sex hormones
What are the functions of steroids?
- cell membrane component in animals (cholesterol)
- sex hormones (testosterone, estrogen)
- in medicine to reduce inflammation
What is the structure of waxes?
they have a diversity of chemicals structures; most have long chains of fatty acids that are solid or rings
What are the properties of waxes?
- diverse structures
- most have long chains of fatty acids or carbon rings
- solid at room temperature
- produced in both plants (ex. carnauba wax) and animals (beeswax, earwax)
- hydrophobic (used as waterproof protection)
