Chemistry Of Life

Question 1

Define water and its composition.

Answer 1

• Water is essential to life.
• It is made up of 1 oxygen atom and 2 hydrogen atoms (H2O).
• The hydrogen and oxygen atoms are bonded by covalent bonds and is considered polar.
• The oxygen atom is more electronegative than the hydrogen atoms.
• The attraction between the partially positive (hydrogen) side of an atom and the partially negative (oxygen) side of another atom is called hydrogen bonds.

Question 2

What are concave and convex meniscus?

Answer 2

• Meniscus are the curved upper surfaces of a liquid in a tube.
• They happen because the fluid is more attracted to the container than it is to itself.
• The molecules of a glass is more polar than the liquid itself that makes it more attractive to water.
• We see a concave one with water in a tube.
• We see a convex one with mercury in a tube.

Question 3

What is a capillary action?

Answer 3

• When a tube is placed in the middle of a tub of water, the water inside the tube rises, and that is called capillary action.
• It can also be seen with the absorption of water by paper towels.

Question 4

What is surface tension?

Answer 4

•The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules.

Question 5

What makes water a good solvent?

Answer 5

• It’s polarity makes it a good solvent.
• Hydrophilic (water-loving) molecules such as NaCl easily dissolves in water while hydrophobic (water-fearing) molecules such as Hexane, a hydrocarbon, do not dissolve in water.

Question 6

What are the properties of water?

Answer 6

• Life is dependent on it.
• It is polar, a good solvent, and has cohesive and adhesive properties.
• It also has high heat capacity and high heat of vaporization.
• And it is less dense as a solid than as a liquid.

Question 7

What are elements?

Answer 7

•These are different substances with different properties at a certain temperature and react in certain ways.

Question 8

What is an atom?

Answer 8

• Atom is the most basic unit of elements.

* It is very small but still has fundamental particles which are protons, electrons and neutrons.

Question 9

What are protons, neutrons, and electrons?

Answer 9

• They are the fundamental particles of an atom.
• A proton is a positively charged particle, an electron is a negatively charged particle, and a neutron is neutral.
• Protons and neutrons are inside a nucleus while the electrons somehow moves around the nucleus.

Question 10

Define carbons

Answer 10

•Carbon is essential for life or it is said to be the backbone of life.
•The most common isotope of carbon is carbon-12 which has 6 protons, 6 neutrons, and 6 electrons, out of these 6 electrons four are valences.
•Carbon is approximately 18% of the body’s mass.
An example of a molecule that has carbon in it is Methane, an organic molecule and also considered to be a hydrocarbon because it has only hydrogen and carbon atoms in it.

Question 11

What are the common functional groups?

Answer 11

A. Hydroxyl Group (R-O-H) - turns an entire molecule into an alcohol, polar, hydrophilic
B. Sulfhydryl Group (R-S-H) - less polar than the hydroxyl group, hydrophilic
C. Carbonyl Group (C=O) - polar, hydrophilic
D. Carboxyl Group (O=C-O-H) - acidic, hydrophilic
E. Amino Group (H-N-H) - basic, hydrophilic
F. Methyl Group (CH3) - when bonded to hydrocarbons becomes hydrophobic
G. Phosphate Group (O=P-O3)

Question 12

What are some of the elemental building blocks of biological molecules?

Answer 12

Biological Molecules tend to be made up of the same set of elemental building blocks:

• Amino Acid - (building blocks of proteins) is made up of C, H, O, N.
• Adenosine Triphosphate (ATP) - (molecular currency of energy) is made up of C, H, O, N, P.
• Triglyceride (“fat molecule”) - (used for energy storage) is made up of C, H, O.
• Deoxyribonucleic acid (DNA) - is made up pf C, H, O, N, P.

Question 13

What are ionic bonds?

Answer 13

• Ion means charged; Bond is the sticking together of atoms.
• Ionic bonds are type of linkages formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
• Cation is a positively charged ion while Anion is a negatively charged ion.

Question 14

What are covalent bonds?

Answer 14

• It is the sharing of electrons for the atoms to be stable.
• A polar covalent bond means that one of the two atoms has more charge than the other, this is due to the electronegativity of the atoms.

Question 15

What is dehydration synthesis or a condensation reaction?

Answer 15

• Dehydration synthesis is the creation of larger molecules from smaller monomers where a water molecule is released.
• Example: 2 glucose monomers, or monosaccharides, combine and produce maltose, a disaccharide, and water

Question 16

What is hydrolysis?

Answer 16

• It is the breaking down of polymers using water.

* It is the opposite of dehydration synthesis.

Question 17

What is the molecular structure of DNA?

Answer 17

• DNA stands for deoxyribonucleic acid.
• -Nucleic because it is found in the nucleus of eukaryotes.
• Each DNA molecule is made up of a chain called nucleotides.
• Each nucleotide are composed of a phosphate group, ribose, and nitrogenous base.
• The phosphate group makes it an acid.
• The ribose leaves an OH or hydroxyl group that makes it deoxyribose.
• The nitrogenous base can be purines, with two rings, or pyrimidines, with one ring.
• Purines can be Adenine or Guanine.
• Pyrimidines can be Thymine, Cytosine, —or Uracil in RNA.
• The purines and pyrimidines are bonded by hydrogen bonds.

Question 18

Why is it called nitrogenous bases?

Answer 18

•Because the nitrogens are really electronegative and they can take up more hydrogen protons.

Question 19

What are phosphodiester linkages?

Answer 19

•Allows the backbones (phosphate group and ribose) to link up.

Question 20

Why is DNA strands has an antiparallel structure?

Answer 20

•Antiparallel because the backbones are pointed in different directions.

Question 21

What is the molecular structur of RNA?

Answer 21

• The differences between RNA and DNA is that the RNA has a hydroxyl group attached to the 2 prime carbon of its ribose and the Thymine in DNA is Uracil in RNA.
• Uracil is like Thymine but without the methyl group.
• It is a little bit more error prone and less stable.

Question 22

What is the process of protein synthesis?

Answer 22

• DNA produces more DNA by replication.
• During transcrption, mRNA takes information from the DNA.
• tRNA grabs amino acids and translate the information to produce proteins.
• rRNA has the structural role in the ribosome.
• MicroRNA, short chains of RNA, can be used to regulate the translation of other RNA molecules.

Question 23

What are amino acids? And what is its molecular structure

Answer 23

• They are the building blocks of proteins.
• The amino group is why it is called an amino; the carboxyl group is why it is an acid; and in between them is the alpha carbon.
• The alpha carbon has covalent bond to the amino group, carboxyl group, and hydrogen.
• The difference between amino acids is the fourth covalent bonds to the alpha carbon — R groups.
• They define the shape of proteins, how they interact with their environment and the types of things they can do.
• Amino acids connect through peptide bonds.
• Peptide is the term for two or more amino acids connected together.

Question 24

What are the 4 types of protein structure?

Answer 24

• Primary structure is just the order/sequence of the amino acids.
• Secondary structure is due to the interaction of the backbone of the amino acids.
• There are three subtypes of secondary structure namely: parallel beta-pleated sheet, antiparallel beta-pleated sheet, and alpha helix.
• Tertiary structure is due to the interaction of the side chains of the amino acids, the sides can be hydrophobic or hydrophilic, etc.
• Quaternary structure is the arrangement of multiple peptide chains of amino acids.

Question 25

What are carbohydrates?

Answer 25

• They are saccharides or “sweet”. •Glucose, a monomer, is a monosaccharide which is also the building blocks of Glycogen, a polysaccharide.
• Carbohydrates are used for energy and has the structural role for plants.

Question 26

What are triglycerides?

Answer 26

• They are fats/oils. Also known as Triacylglycerol.
• Glycerol/glycerine, a sugar alcohol, is a three-carbon chain with an OH group attached to each carbon.
• Fatty acids are long carbon chains, that makes them hydrophobic, with a carboxyl group which is an acid.
• Through dehydration synthesis, the OH groups from the glycerol form bonds with the carboxyl groups of three fatty acids.
• Acyl is a functional group where you have a carbon that’s part of a carbonyl group bonded to an organic chain and then to something else (O=C-Rx).
• Ester is like Acyl but the carbon is bonded to an organic chain and then bonded to an Oxygen which is bonded to an organic chain also (O=C-RO-R).

Question 27

What are saturated, unsaturated, polyunsaturated, and trans fats?

Answer 27

• In saturated fats, the carbons of the fatty acids of a triglyceride are all bonded to hydrogens and are able to be relatively dense/solid.
• In unsaturated fats, a carbon of a fatty acid of a triglyceride does not have enough hydrogens to keep it stable so it forms a double bond to the next carbon that makes it more likely to be liquid.
• Polyunsaturated fats are just like the unsaturated fats but with multiple double bonds; also liquid.
• Trans fats are like unsaturated fats but with the trans configuration which makes more linear and don’t bend. They are not typically found in nature and very unhealthy.