Ch. 3 The Chemical Basis of Life Flashcards
1
Q
Functional groups
A
- groups of atoms with special chemical features that are functionally important
- each type of functional group exhibits the same properties in all molecules in which it occurs
- most organic molecules and macromolecules contain functional groups
1
Q
Condensation/dehydration reaction
A
- links monomers to form polymers
- generates one water molecule for each monomer added
- can repeat for thousands of monomers
- catalyzed by enzymes
2
Q
Carbohydrates
A
- Cn(H2O)n
- most of the carbon atoms in a carbohydrate are linked to a hydrogen atom and a hydroxyl (OH) group
- composed of carbon, hydrogen, and oxygen atoms
3
Q
Monosaccharides
A
- monomers of carbohydrates
- pentoses (5 Cs)
- ribose and deoxyribose
- hexoses (6 Cs)
- glucose
4
Q
Disaccharides
A
- composed of two monosaccharides
- joined by dehydration/condensation
broken by hydrolysis - joined by glycosidic bond
- ex: sucrose, maltose, lactose
5
Q
hydrolysis
A
- polymers broken down into monomers
- a molecule of water is added back each time a monomer is released
- can repeat to break down long polymers
- catalyzed by enzymes
6
Q
Glycosidic bond
A
covenant bond that joins monosaccharides to form carbohydrates
7
Q
polysaccharides
A
- maney monosaccharides linked together to form long polymers
8
Q
two types of Energy storage polysaccharides
A
- starch (plants)
- glycogen (animals)
- structure is more branched, so it can be broken down more easily, making it a good energy source but doesn’t have good structural integrity
9
Q
Structure polysaccharides
A
- Cellulose
- chitin
- glycosaminoglycans
- since, its more condensed and has H-bonding between the layers, it is better for structure but isn’t broken down as easily for energy
10
Q
Fats/triglycerides
A
- Formed by bonding glycerol to 3 fatty acids
- joined by dehydration; broken by hydrolysis
11
Q
Saturated fats
A
- all carbon linked by single bonds
- tend to be solid at room temperature
- fully saturated in C-H bonds
- animal fats usually saturated
12
Q
Unsaturated fats
A
- contain one or more double bond
- tend to be liquid at room temp.
- cis forms naturally
- trans formed artificially & is linked to disease
- plant fats usually unsaturated
13
Q
Phospholipids
A
- formed from glycerol, two fatty acids, and a phosphate groups
- amphipathic molecules (polar phosphate head w/ non polar fatty acid tail)
14
Q
phospholipid bilayer
A
- can be more or less fluid depending on the types of phospholipids that make it up
- each side is called a leaflet of phospholipids
- the individual phospholipids are independent of each other (not bonded)
- trapped in place by polarity
15
Q
Proteins
A
- peptide/polypeptide with a specific function
- composed of C, H, O, N and small amounts of other elements like S
- made of amino acids
16
Q
lipids (makeup and examples)
A
- composed of predominantly hydrogen and carbon atoms
- non polar
- includes fats, phospholipids, steroids, and waxes
- on average, make up about 40% of organic matter in the human body
17
Q
amino acids
A
- monomers of proteins/polypeptides
- 20 types of amino acids
- amino group - positively charged
- R group - side chain that determines structure and function
- carboxyl group - negatively charged
18
Q
Polypeptide formation
A
- amino acids join to form peptide bonds via dehydration reaction
- proteins may be formed from one or several polypeptides
- a polypeptide isn’t necessarily a protein
19
Q
primary protein structure
A
- amino acid sequence
- encoded directly by genes
- first amino acid will always have its amino group exposed (amino terminus)
- last amino acid will always have its carbonyl group exposed (carbonyl terminus)
20
Q
Secondary protein structure
A
- chemical and physical interactions cause protein folding
- alpha helices and beta pleated sheets are key determinants of a protein’s characteristics
- “random coiled regions” - not helix of pleated sheet
- shape is specific and important to function
21
Q
Tertiary protein structure
A
- folding gives proteins complex 3D shapes
- final level for a single polypeptide chain
22
Q
Quaternary structure
A
- made of two or more polypeptides coming together to change the functionality
- ## made of individual polypeptides called protein subunits
23
Q
5 factors promoting protein folding and stability
A
- H-bonding
- ionic bonds and other polar interactions
- hydrophobic effects
- Van der Waals forces
- Disulfide bridges
24
Q
Protein-protein interactions
A
- polypeptides must fit by both shape and charge
- four factors to bind:
1. H-bonding
2. ionic bonds and other polar interactions
3. hydrophobic effects
4. Van der Waals forces
25
Q
glucose isomers
A
ex: glucose and galactose
- alpha glucose - hydroxyl group below ring
- beta glucose - hydroxyl group above ring
-
26
Q
what affects how proteins interact
A
- hydrogen bonds
- ionic bonds and other interactions
- hydrophobic effects
- Van der Waal forces
- protein conformation (must fit)
- likely no covalent bonds
27
Q
modules/domains of proteins
A
- distinct structures of proteins that have specific functions
- proteins that share a particular domain also share the associated function
28
Q
two classes of nucleic acis
A
- deoxyribonucleic acid (DNA)
- ribonucleic acid (RNA)
29
Q
DNA vs. RNA
A
- DNA stores genetic information encoded in the sequence of nucleotide monomers
- RNA decodes DNA into instructions for linking together a specific sequence of amino acids to form a polypeptide chain
- both made from nucleic acids
- DNA has thymine, RNA has uracil
- DNA has one form and RNA has several
- RNA has some enzymatic functions
30
Q
3 parts of a nucleic acid
A
- phosphate group
- five-carbon sugar (ribose or deoxyribose)
- nitrogenous base
31
Q
types of nitrogenous bases
A
purines
- Adenine and Guanine
- have two rings
pyrimidines
- cytosine and thymine
- have one ring
Cytosine-Guanine is stronger because it has 3 H-bonds instead of 2
32
Q
Structure of DNA
A
- two strands in a double helix
- 3’ of one carbon connects to the 5’ of the next
-3’ exposed on one side, 5’ on the other
33
Q
A
