All about Carbon Flashcards
what makes carbon a unique element? Provide examples.
The pure form of carbon acquires a large variety of molecular structures, and also shares properties of both metals and nonmetals. Ex: DIAMONDS (made from carbon) is clear and translucent but does not have metal luster or conduct electricity; hence seems like nonmetal.
but GRAPHITE- has metallic gloss and conducts electricity- which are metal characteristics.
What differentiates Carbon from water? What kind of hybridization does Carbon have?
Carbon unlike water (polar) is NONPOLAR. Carbon’s electron shell is half completed and can complete their shell by either donating or accepting the same number of electrons (4). They can form 4 covalent bonds, without a shift in e- density. Have sp3 hybridization.
what is the unique feature of Carbon (structure wise)?
Carbon can form long covalent chains with other carbon atoms and form chains, branched trees, and rings (cycles). also biomolecules are carbon based. Carbon nanostructures are also carbon-based polymers that are useful for biomolecule anchors and surface structures.
what are the similarities between Carbon and Silicon? Why is Silicon not as stable as Carbon?
Silicon and Carbon can both form bonds with up to 4 atoms at the same time. Silicon-based polymers are LESS STABLE and more reactive than carbon.
This occurs because silicon has more metallic properties and higher affinity of binding to oxygen atoms.
silicon oxide (SiO2) can form hard crystals with Si atoms bound to 4 Oxygens. This bond is very strong and hard to break, LIMITS FLEXIBILITY of oxidized silicon and are NOT SOLUBLE, NOT POSSIBLE TO EXHALE.
Discuss the reason behind Carbon’s stability in terms of double bond formation. How does it benefit biochemical molecules?
The Double bonds present in carbon chains (like ethene) prevent free rotation of bonds around axis, which leads to stability of carbon and has major influence on 3D shape of macromolecules. 3D structure important for physiological/biochemical activity.
What are the benefits of alternating double bonds in Carbon? what is an example?
alternating double bonds of carbon chains allow bonding e- to move within molecules, stabilizing structure and creating RESONANCE. ex; benzene rings.
Differentiate between stereoisomers, enantiomers and chiral centers.
Stereoisomers have identical chemical formula and molecular weight, but different 3D structures (ex: maleic acid and Fumaric acid). these structure can be differentiated with cis and trans labels depending on location of functional groups with double bond.
Enantiomers- optical isomers that are mirror images of each other, similar chemical properties, but non-superimposed . Ex: L amino acid vs D- amino acid, or left hand vs right hand.
Chiral center- atom with 4 different chemical groups attached to it.
What are hydrocarbons?
Carbon- Hydrogen compounds that are insoluble in water, cannot form H-bonds and are NONPOLAR (not enough power to shift e- density). These hydrophobic atoms usually stick to each other. Ex: oil and water mix., methyl groups, methane groups (CH4), seen in fatty acid tails.
Describe Hydrophobic Interactions and how it contributes to stability of macromolecules.
Hydrophobic interactions occur between 2 nonpolar molecules and only happen in polar, water environments.
Interactions are NOT due to intrinsic attraction between nonpolar groups. result from system achieving great thermodynamic stability (minimize # H2O molecules around hydrocarbons).
Rather, when hydrocarbons are in water, they stick to each other, to avoid water, which stabilizes macromolecular assemblies in cell.
What is the driving force of protein folding?
Hydrophobic (nonpolar) interactions.
what are hydrophilic molecules?
Substances that are water soluble, and dissolve in water by forming H-bonds with water molecules.
also polar groups that are attached to biopolymers (OH, C=O, NH2, HPO3) are water soluble (hydrophilic).
How do polar interactions stabilize biomolecules? Provide examples of this application
Polar interactions through H-bonds (non-covalent bond) can stabilize biomolecules. Ex: amino acids in a polypeptide chain are hydrogen-bonded together into folded protein. Also, the bases(like, G and C) in a double-helix (DNA) are H-bonded.
What are the four types of noncovalent bonds?
Ionic bonding, H-bonds, Van Der Waals, and Hydrophobic bonds.
What kind of bonds introduce polar groups in biopolymers? List examples of the bond groups.
C-O bonds and C-N bonds. Polar oxygen- containing groups define reactivity of biomolecules. Nitrogen- containing groups form positively charged groups, govern interactions between molecules and form polar interactions.
C-O groups- Hydroxyl (OH), carbonyl aldehyde or ketone), Carboxylic acids (COOH) and Esters (alcohol and acid- COOH an OH to O=C-O)
C-N groups - Amines (NH2) in water combine with H* to form positive charge. Amides formed by combining carboxylic acid and amine (COOH and NH2) Amides are uncharged in water. Nitrogen also in ring compounds (purines and pyrimidines of nucleic acids)
Describe the benefit of phosphates for biomolecules. What kind of functional groups do these phosphates form? What are high-energy bonds?
Phosphate groups introduce negative charges into biomolecules (nucleic acids and proteins). Phosphates can change shape or folding of protein or inactivate/activate enzymes (transfer of phosphates) inorganic phosphate (HO-P=O-O-O) is stable ion formed from H3PO4. Phosphate esters formed from phosphate and free OH group form phosphate groups that attach to proteins.
phosphate and COOH (metabolite), or 2 or more phosphate groups (ATP) form acid anhydrides which are known as high-energy bonds since they release large amount of free enegy when bond broken by hydrolysis
