Chapter 1: Molecules and Fundamentals of Biology Flashcards
Intramolecular Forces
Hold atoms together within a molecule
Intermolecular Forces
Forces between molecules; Affect physical properties
Monosaccharide
CH2O
Ribose
5 C monosaccharide
Fructose
6 C monosaccharide
Glucose
6 C monosaccharide
Glucose and Fructose are ______
Isomers
Disaccharides are held together by _____ bonds resulting from ____ reactions
Glycosidic; dehydration(condensation)
Sucrose
Glucose + Fructose disaccharide
Lactose
Glucose + Galactose disaccharide
Maltose
Glucose + Glucose disaccharide
Starch
Energy storage for plants
Starch is an ____ bonded polysaccharide
Alpha
Amylose
Linear starch
Amylopectin
Branched starch
Glycogen
Energy storage for animals
Glycogen is an ___ bonded polysaccharide much ___ branched than starch
Alpha; More
Cellulose
Structural component of plant cell walls
Cellulose is a ___ bonded polysaccharide
Beta
Chitin
Structural component of fungi cell walls
Chitin is a ___ bonded polysaccharide with the element ___ added to each monomer
Beta; Nitrogen
Proteins
CHON
Amino Acid Structure
Amino, Hydrogen, Carboxyl, R-group
Polypeptides are polymers of ___ joined by ___ bonds through ___ reactions; ___ reactions break these bonds
Amino acids; Peptide; Dehydration; Hydrolysis
N-terminus (amino terminus)
Side of polypeptide that ends with an amino group
C-terminus (carboxyl terminus)
Side of polypeptide that ends with a carboxyl group
Primary structure
Group of amino acids
Secondary structure
Intermolecular forces between polypeptide backbone due to hydrogen bonding
Tertiary structure
Due to interactions between R-groups; may create hydrophobic or hydrophillic spaces
___ bonds are created between two cysteine aa’s
Disulfide
Protein structure may be one of three
Fibrous, globular, intermediate
Protein composition may be one of two
Simple (aa’s) or complex (aa’s +other components)
Protein functions (7)
Storage, hormones, receptors, motion, structure, immunity, enzymes
In protein denaturation, only the ___ structure is affected
Primary
Reasons a protein may denature (3)
High or low temperature, pH changes, salt concentration
The transition state is the ___ intermediate between reactants and products
Unstable
Specificity constant measures how ___ an enzyme is at binding to a substrate, converting it to a ___
Efficient; product
Induced fit theory describes how the active site ___ itself and changes ___ to fit the substrate
Molds; shape
Ribozyme
RNA molecule that can act as an enzyme (non-protein)
Cofactor
Non-protein molecule that helps enzymes perform reactions
Coenzyme
Organic cofactors such as vitamins
Inorganic cofactors are usually ___ ions
Metal
Holoenzymes are enzymes that are ___ to their cofactors
Bound
Apoenzymes are enzymes that are ___ to their cofactors
Not bound
Prostetic groups are cofactors that are ___ to their enzymes
Tightly/Covalently bound
Competitive inhibition occurs when a ___ competes ___ with the substrate for active site binding
Competitive inhibitor; directly
Noncompetitive inhibition occurs when a ___ binds to an ___ modifying the active site
Noncompetitive inhibitor; allosteric site
Allosteric site
Location on enzyme that is different from the active site
In competitive inhibition, the rate of enzyme action ___ be increased by adding more substrate
Can
In noncompetitive inhibition, the rate of enzyme action ___ be increased by adding more substrate
Cannot
Enzyme kinetics plot
Used to visualize how inhibitors affect enzymes
Enzyme kinetics plot: x-axis:___, y-axis___, Vmax___, Michaelis constant (Km)___
Substrate concentration [X}; Reaction rate or velocity (V); Maximum reaction velocity; Substrate concentration at which velocity is 50% max
___ occurs when all active sites are occupied
Saturation making graph plateaus
Competitive inhibition -> Km ___ while Vmax ___
Increase; Stays the same
Noncompetitive inhibition -> Km ___ while Vmax ___
Stays the same; Increases
Lipids
CHO
Lipids have long ___ tails making them very ___
Hydrocarbon; Hydrophobic
Triacylglycerol is a ___ molecule with a ___ backbone and ___ fatty acids
Lipid; Glycerol; Three
The glycerol and fatty acid tails in triacylglycerol are connected by ___ linkages
Ester
Saturated fatty acids ___ double bonds
Have no
Unsaturated fatty acids ___ double bonds
Have
___ unsaturated fatty acids have kinks that cause the tails to bend
Cis
___ unsaturated fatty acids have straighter tails
Trans
Phospholipids
Glycerol backbone, one phosphate group, two fatty acids
In phospholipids, the phosphate group is ___ and the fatty acids are ___
Polar; Nonpolar
Is cholesterol amphipathic?
Yes
Are phospholipids amphipathic?
Yes
Cholesterol is the most common precursor to ___ hormones
Steroid
Cholesterol is the starting material to ___ and vitamin ___
Bile; C
Factors that influence membrane fluidity (3)
Temperature; Cholesterol; Degrees of unsaturation
Lipoproteins allow passage of ___ molecules
Lipid
___ density lipoproteins “bad cholesterol” deliver cholesterol to peripheral tissues
Low
___ density lipoproteins “good cholesterol” deliver cholesterol to the liver to make ___
High; Bile
___ are simple lipids that have long fatty acid tails connected to ___ alcohols through ___ linkages
Waxes; Monohydroxyl; Ester
___ are lipid derivatives containg long carbon chains with ___ double bonds and ___ at each end
Carotenoids; Conjugated; Six membered rings
Carotenoids function as ___
Pigments
Nucleic Acids
CHONP
Nucleosides contain a ___ carbon sugar and a ___ group
Five; Phosphate
___ sugars contain a hydrogen at the 2’ carbon
Deoxyribose
___ sugars contain a hydroxyl group at the 2’ carbon
Ribose
Purines are and have ___ rings
A, G; Two
Pyrimadines are ___ and have ___ rings
C, U, T; Three
___ bonds connect the phosphate group of one nucleotide (at the ___ carbon) to the ___ group of another nucleotide (at the ___ carbon)
Phosphodiester; 5’; Hydroxyl; 3’
Nucleic acid polymerization proceeds at the ___ end
3’
How many times can A H-bond to T? G to C?
2; 3
Central dogma of genetics
DNA -> RNA -> Proteins
Exceptions to the central dogma of genetics
Reverse transcriptase, Prions
RNA world hypothesis
RNA dominated Earth’s primordial soup before there was life; Developed self replicating mechanisms and later could catalyze reactions to make more complex molecules;
RNA is ___ and ___
Reactive; Unstable
