Chapter 4: Carbon and the Molecular Diversity of Life & Chapter 5: Structure & Function

Why is carbon so important & versatile?

• can form large, complex molecules that serve as the backbone of biological molecules, due to its ability to bond with other atoms in multiple ways, including four covalent bonds.

• make up most organisms (vague but basically makes up their cells & structures to perform their functions correctly)

• 4 bonds, making chains and rings that can vary in length and shape, allowing for an immense variety of structures and functions in living organisms.

• macromolecules: nucleic acids, proteins, lipids, and carbs are all made up of carbon

• its place on the periodic table ( 6 protons & 4 valence electrons

What are each of the macromolecules & their monomers/polymers

• Carbohydrates: monomers are monosaccharides (simple sugars), polymers are polysaccharides (e.g., starch, glycogen)

• Lipids: N/A, but they are made of fatty acids (not an example of a monomer)

• Proteins: monomers are amino acids, polymers are polypeptide chains

• Nucleic acids: monomers are nucleotides, and polymers are nucleic acids (ex: DNA & RNA)

Major elements present in each macromolecule

Elements: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur

Carbs: CHO

Lipids: CHO (sometimes they contain N&P)

Proteins: CHONS

Nucleic Acids: CHONP

Organic vs. Inorganic Compounds

• Organic: Molecules built around carbon atoms, typically containing carbon-hydrogen (C-H) covalent bonds. (ex. Glucose, methane, DNA, proteins, and fats)

• Inorganic: Substances that generally do not contain carbon-hydrogen bonds. (ex. Water (H2O), table salt (NaCl), and carbon dioxide (CO2)

Can organic molecules form under conditions estimated to simulate those on the early Earth?

• Organic molecules, a first step in the origin of life, may have been synthesized abiotically on the early Earth, some experiments mimic the correct environments for this to occur.

• This question allowed for the shift from vitalism to mechanism then view that physical and chemical laws govern all natural phenomena, including the processes of life.

Our life is…

CARBON BASED YIPPPPPEEEEE

Octet (specific to carbon)

• atoms are more stable when they are sharing electrons —> 4 covalent bonds to fill the octet

Why can carbon form a stable backbone for long chains?

• Carbon to carbon bonding is unusually strong which makes it perfect for being able to support large molecules

• Carbon can also form many covalent bonds to as many as 4 molecules which allows the chains to grow very large

What are hyrdocarbons?

• organic molecules consisting of only carbon and hydrogen

• they make good fuels due to their storage of energy

• form the tails of large molecules

What are the functional groups?

• hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate

What is an isomer?

• compounds that have the same numbers of

  atoms of the same elements but different structures and

  hence different properties.

Structural isomers

• differ in the covalent arrangements

  of their atoms.

Cis-trans isomers

carbons have covalent bonds to the same atoms, but these

atoms differ in their spatial arrangements due to the inflexi-

bility of double bonds.

Enantiomers

isomers that are mirror images of each

other and that differ in shape due to the presence of an

asymmetric carbon, one that is attached to four different atoms

or groups of atoms. (but they still are different —> can drastically change the molecule that is present)

Enzymes

specialized macromolecules that speed up chemical reactions.

dehydration reaction/synthesis

Monomers are connected by a reaction in which two mol-

ecules are covalently bonded to each other, with the loss of a

water molecule;

hydrolysis

Polymers are disassembled to monomers, The bond be-

tween the monomers is broken by the addition of a water mol-

ecule,

Storage Polysaccharides

Plants store starch, a polymer of

glucose monomers, as granules within cellular structures

known as plastids, which include chloroplasts.

chitin

carbohydrate used by arthropods (insects, spiders, crus-

taceans, and related animals) to build their exoskeletons

If it ends in “ol” is it an….

alcohol!

fatty acid

a long carbon skeleton, usually 16 or 18 carbon atoms in length.

saturated fatty acid & unsaturated fatty acid

saturated fatty acid: no double bonds between carbon atoms (butter, cheese, red meat, and coconut oil)

unsaturated fatty acid: have one or more double bonds (olive oil and avocados)

trans fat

the process of hydrogenating vegetable oils produces not only saturated fats but also unsaturated fats with trans double bonds.

steroids

lipids characterized by a carbon skeleton consisting of four fused rings

Cholesterol

a common component of animal cell membranes and is also the precursor from which other steroids are synthesized.

Catalysts

chemical agents that selectively speed up chemical reactions without being consumed by the reaction.

4 levels of protein structure

primary: The linear sequence of amino acids in a polypeptide chain

secondary: The linear sequence of amino acids in a polypeptide chain.

tertiary: The overall three-dimensional shape of a single polypeptide chain.

quarternary: The assembly of two or more separate polypeptide chains (called subunits) into a single functional protein complex.

chaperonins

protein molecules that assist in the proper folding of other proteins