Major class of Biomolecules Flashcards
What is the chemical composition of the bacterial cell (%) ?
70% water and 30% chemicals (which comporise of inorganic ions, phospholipids (4 kinds), DNA, RNA, Proteins (15%) and polysaccharides ). Majority of chemicals are macromolecules (26%).
Describe relationship between monomers, polymers and residues. List examples for each macromolecule.
Monomers- are small repetitive units that can create large polymers. Residue is what’s left from polymer. Small organic molecules combine to form large organic molecules.
Ex: Sugars form polysaccharides, glycogen (animals) and Starch (plants). Fatty acids from fats and mem lipids. Amino acids- from proteins. Nucleotides form nucleic acids.
Explain the formation and degradation of polymers from subunits and which enzymes are involved.
Formation- multiple subunits form polymers through CONDENSATION reaction with release of water as by product. Enzymes for this include SYNTHASES, POLYMERASES (subunits can be identical or heterogenous).
Break down of polymers or monomers (reversal reaction)- HYDROLYSIS reaction with water being added to to break bond. enzymes include HYDROLASES (also polymerases can catalyze hydrolysis too).
What are residues? provide example of subunits that are identical vs heterogenous.
Residues are the functional groups lost from subunit during a reaction. Homogenous subunits- glucose to form starch.
Heterogenous subunits- amino acids form proteins.
What is ATP? Why is ATP so important in biochemical reactions? what kind of bonds do they have?
ATP (Adenosine Triphosphate)- universal energy intermediate for majority of cell processes. ATP also substrate for RNA Synthesis (nATP form Poly (AMP)n and PPi)
Has phosphoanhydride bonds that provide energy for a lot biochem reactions. ATP is a donor of phosphate groups to many macromolecules, hence changes their activity.
Describe ATP cycle.
Input of energy (ATP) is gained from sunlight or food. ADP will undergo condensation reaction of releasing H20 to join another phosphate group and form ATP. Then ATP will release energy through hydrolysis where addition of water will break ATP bond into ADP an Pi to have energy for intracellular work and chemical synthesis.
What makes Lipids a unique, broad class of biomolecules?
Lipids are NOT formed from repetitive subunits of separate biomolecules. Lipids contain simpler lipid molecules like FATTY ACID residues linked together by ESTER BOND.
Triacylglycerol contains lipids.
What kind of method is used to segregate macromolecules from live cells? How does process work? Differentiate between boundary and band sedimentation?
Ultracentrifugation- uses high speed centrifuge for separating particles by size or density. Method based on sedimentation. most dense particles sink to bottom, while less dense particles move to center of liquid, light particles at top.
process- load sample as narrow band at top of tube, centrifuge it (spin). Can either get heterogenous aggregate (diffuse smear of particles scattered) or homogenous solutions (Ex: Hb protein sediment as single band).
boundary sedimentation- used with heterogenous aggregates, create density gradient- least to most dense (bottom).
Band sedimentation- used with homogenous solution/narrow band. observe where band moves and stays at area equal to density, see which proteins present.
Describe the factors that allow conformations (proteins) to occur and be stable. What happens if conformations are lost? What kind of bonds must be used?
Conformations which are stable structures made from NONCOVALENT BONDS.
When native conformation is lost (bond disrupted), DENATURATION occurs.
Conformations are promoted by environmental conditions (temperature, pH, ionic strength) and CHAPERONES (macromolecules that assist)
What is the function of noncovalent bonds? What are salt bridges?
Noncovalent bonds help maintain neutrality, stabilize native conformation of biopolymers and mediate interactions between macromolecules. Salt bridges are electrostatic interactions between negative(deprotonated weak acid) and positive groups (protonated weak base), form ions. For ex: ionic group with hydrogen bonding
Discuss how each chemical bond is used in biomolecules.
Covalent- form polymeric chains from monomers, bring distant parts of chain together in protein (through disulfide bonds Noncovalent bonds (hydrogen and ionic)- stabilize conformations in biopolymers, interact with other polymers, substrates. Hydrogen bonds- polar, electrostatic interaction between partly charged e-negative atoms and Hydrogen. Ionic interactions- salt bridges are electrostatic interactions that happen between charged groups in macromolecules. Hydrophobic interactions- not actually bonds, of thermodynamic nature (exclude nonpolar groups in polar environment), aid in structure of biomolecules.
What structural feature does starch, glycogen and cellulose have in common? list the structural groups for each sugar.
They all have the same glucose residues that are linked differently.
Starch- alpha 1,4 chain
Cellulose- B, 1,4 (up down)
glycogen- alpha, 1,4 and alpha 1, 6
Differentiate between carbohydrates, monosaccharides, oligosaccharides and polysaccharides. Provide examples
Carbohydrates- organic compounds with chemical formula of C(H2O)n.
Monosaccharides (simple sugars)- small molecules with a few carbon atoms that are capable of CYCLIZATION and being monomeric units of long polymers (ex: glucose)
Oligosaccharides- Polymers with few units such as disaccharides(2 monosaccharides), and trisaccharide. (ex: lactose, sucrose (table sugar)
Polysaccharides- very long polymers (ex: glycogen , starch)
What feature characterizes monosaccharides and disaccharides? What about trisaccharide?
Both monosaccharides and disaccharides have a sweet taste and can also be called sugars.
As oligosaccharides get longer, they lose sweet taste (disappears), as trisaccharide have small amount of sweet taste.
What are common features of carbohydrate structures? List functional groups present.
Carbs can have formuala C(H2O)n with 2 or more OH groups. They can contain aldehyde group (aldoses) or ketone group (ketoses). based on number of carbons (trioses, pentoses, hexoses) or position of particular functional group on carbon Aldoses- glyceraldehyde (3x, aldehyde on first carbon, 2 OH on right, Ribose (aldehyde on 1st C, 5C, 4 OH on right), Glucose (aldehyde 1st, 6C, 1 OH on left for 2nd C) Ketoses dihydroxyacetone (3C, 2 OH on right, carbonyl on 2nd C), Ribulose (carbonyl on 2nd C, 5C total, Oh on right) , fructose (6C total, carbonyl 2nd C)
