Topic 2 & Some Topic 7: Molecular Biology Flashcards
DP2- U1: Biochem
A. Chemical Elements and Water
1.define molecular biology
the study of living processes in terms of the chemical substances
A. Chemical Elements and Water
2.contrast the synthesis of urea in the body and artificially.
i.what urea +ii. body/transportation/path+iii. why artifical/steps/path
i.
urea is produced in our body as a way of excreating nitrogen from excess amino acids
ii.
- synthesized in the liver and uses enzymes.
- urea to blood stream to kidneys to filtered and released by urine.
- cyclic chemical pathway and complex
iii.
- artifical is done to help produce millions of tons of nitrogen fertilizers for crops
- 2 main steps & does not use enzymes + is identical to normal urea
- linear and simple
A. Chemical Elements and Water
3.Outline how the artificial synthesis of urea lead to the falsification of theories.
i.what is the theory/meaning ii. Who and how did they falsify it
i.
- Vitalism theory: the orgin and phenomena of life are due to a vital principle which is different from purely chemical or physical forces. Organic compounds in plants/animals could only be made with the help of a vital principal
ii.
Wöhler accidentally falsified this theory by artifically synthesizing urea in 1828 when trying to prepare ammonium cynate. Since Wöhler created urea it undermined the theory of needing a vital force to create an organic compound.
A. Chemical Elements and Water
4.Explain how the chemical properties of carbon allows for a diversity of compounds.
i.type/strength of bond ii.form how many bonds? and example
i.
- form covalent bonds
- strongest intramolecular force because they evenly share electrons. thus, no confilict to weaken the arrangement.
ii.
- contains 4 electrons in valence shell allowing them to form 4 covalent single bonds with other potential elements.
ex. methane= CH4
A. Chemical Elements and water
5.Outline the four classes of carbon compounds
i. elements in each class ii. made of/properties iii.examples or use
a. Carbs
i. (C, H, O)
ii. 1 or more simple sugars (monomers). Many monomers make monosacchride which make polysacchrides
iii. startch, cellulose, glycogen
b. Lipids
i. (C, H, O)
ii. insoluble in water, soluble in nonpolar organic solvents
iii. triglycerides (fats, oils), phospholipids, steriords
c. Protiens
i. (C, H, O, N) sometimes sulphur
ii. large organic compounds made up of amino acids
iii. use protiens for hormones, enzymes, gas transport etc.
d. Nucleic Acids
i. (C, H, O, N, P)
ii. covalently bonded sugars (ribose= RNA, deoxyribose= DNA) , phosphates, and bases to form nucleotides which are what the chains are made up of.
iii. RNA and DNA
A. Chemical Elements and water
10.Explain Water Polairity
what is polarity/how is water polar
water is polar because the covalent bond formed between the oxygen molecule and two hydrogen molecules exhbit an unequal share of electrons and unsymmetrical shape. This in turn creates two poles in the molecule; one being partialy negative (oxygen) and one being partially positive (hydrogen). This unequal share of electrons then makes the molecule polar and is also known as a dipole.
These dipoles attract other polar compounds and H2O molecules associate via hydrogen bonding between the H and O areas on many molecules.
A. Chemical Elements and water
12.Outline the four properties of water giving an example of each
and how the property is formed
1. Cohesion
defn: water sticking to water because of close attraction forming a tight sticky pack
how: the polairty and electronegativity difference of water
ex: A simple example of cohesion in action comes from the water strider (below), an insect that relies on surface tension to stay afloat on the surface of water.
2. Adhesive
defn: water sticking to polar surfaces
how: same reason they stick to themselves- polairty, h-bonds, delta electronegativity
ex: Capillary action- able to adhere H2O molecules to the polar surface of the xylem cellulose vessel. also ex of cohesion since the water molecules are sticking to themselves.
3. Thermal
defn: relating to changing the state or temp of water by energy (usually heat). Heat capacity of water is 4.186 J/g ºC= that much energy needed to heat a gram of water by 1ºC
how: stength of h-bonds allows for a lot of energy needed to change the state/temp of water. Causes water to heat or cool more slowly than other substances.
ex: stable internal enviroment for all living things because water cant change temp too easily. (humans are made up of 70% water)
4. Solvent
defn: water being able to dissolve other polar substances.
how: waters polarity (large amounts) allows it to interupt intramolecular forces allowing it to dissociate atoms. reason it is a great solvent
ex: salt & water; Na+ is surrounded by O- regions whereas Cl- is surrounded by H+ regions allowing the crystal lattice to dissociate and pull apart.**
A. Chemical Elements and water
13.Contrast hydrophilic and hydrophobic
add examples
hydrophilic: polar or charged substances that are chemically attracted to water. Can dissolve in H2O. ex. glucose, sodium and chlorine ions, cellulose surfaces
hydrophobic: non-polar and uncharged substances that are chemically unattracted to water. cant dissolve in H2O. ex. fats, oils, alcohols
A. Chemical Elements and water
14.Compare the thermal properties of water and methane.
only need to memorize two for each molecule
methane
formula: CH4
Polarity: non-polar
density gm c-3 :0.46
specific heat capacity Jg-1ºc-1: 2.2
Latent heat of vapourisation J g-1: 510
melting point ºC: -182
boiling point ºC: -161.6
water
formula: H2O
Polarity: polar
density gm c-3: 1
specific heat capacity Jg-1ºc-1: 4.18
Latent heat of vapourisation J g-1: 2240
melting point ºC: 0
boiling point ºC: 100
Latent heat of vapourisation: energy from liquid to gas
A. Chemical Elements and Water
15.Outline the use of water as a coolant in sweat.
what property of water states water is a good coolent+ expectation
Water’s thermal property mentions how 1g of water must absorb 4.18 Jg-1ºC of heat before the temperature is inceased by 1ºC (SHC). thus, water is a good coolant as it can absorb heat easily but changes its temp slowly.
in order for humans to maintain a stable internal heat temp of 37ºC, when we are overheating, we sweat. sweat is made up of 99% of water so it can absorb the heat easily and simply be removed. #homeostasis
A. Chemical Elements and water
16.Outline the transport of sodium chloride, amino acids, glucose, oxygen, fat molecules and cholesterol.
i. solubility in water/ ii. how is it carried in the blood
Glucose:
i. polar thus soluble
ii. blood plasma (consists of 95% water and other substances which are transported)
Amino acids:
i. polar because of amine and acid groups + negative and positive charges. even if the R-groups are nonpolar it just effects the degree of solubility.
ii. blood plasma
sodium chloride:
i. ionic compound thus polar and soluble. dissolves to form Na+ and Cl- ions
ii. blood plasma
Oxygen:
i. nonpolar but due to small size it is soluble in water. as the H2O temp goes up the solubility of oxygen decreases.
ii. hemoglobin in red blood cells carries the majority of oxygen. 4 binding sites of oxygen. at normal body temp very little oxygen can be carried by the plasma.
cholestrol:
i. insoluble- mainky hydrophobic except for head. too small to be significant.
ii. carried in the blood plasma by lipoprotiens.
fats:
i. insoluble- large non-polar molecules
ii. blood plasma by lipoprotiens
lipoprotiens: outer layer of phospholipds hydrophilic heads out and hydrophobic tales inside. Hydrophobic ends in contact with non-polar end of cholestrols, fats and protiens.
A. Chemical Elements and water
17.Explain (with examples) how disaccharides and polysaccharides can be formed from monosaccharide monomers.
be able to draw it
glucose + glucose → maltose + water
glucose= monomer
maltose= disaccharide
→= condensation reaction (when water product is formed from each of the reactants)
the hydrogen attached to Carbon-1 on one glucose molecule and the HO group attached to Carbon-4 on another glucose molecule dissociate by an enzyme to form water product.
maltose is formed by creating a glycosidic bond (covalent bond with oxygen in the middle) between carbon-1 and carbon-4. This oxygen comes from the OH molecule attached to carbon-1 on the same molecule that gave up the hydrogen from carbon-1 (removed by enzyme).
B. Carbohydrates & Lipids
18.Use visualization software (i.e. Jmol) to compare cellulose, starch and glycogen.
compare the structure of these molecules with glucose/fructose/sucrose
look at other document with drawings
B. Carbohydrates & Lipids
19.Compare the structure and function of the polysaccharides cellulose, starch and glycogen.
Cellulose
structure: 1-4 bonds of beta glucose molecules. straight (chain as each subunit flips) and unbranched.
function: used in cell walls and prevents plants from bursting under high tugor pressure. high tensile strength due to H-bonds, insoluble in water.
Startch
function: useful for glucose and energy storage in plants. stored temporarly in leafs when more glucose is made than for transport. insoluble, easy to add and remove glucose units.
Amylose:
structure: 1-4 bonds of alpha glucose molecules. straight and unbranched chain, forms a helix shape.
Amylopectin
structure: 1-4 and 1-6 glycosidic bonds of alpha glucose molecules. bent and branched, forms a globular shape.
Glycogen
structure: 1-4 and many 1-6 bonds of alpha glucose. bent and branched chain, forms a compact shape.
function: useful for glucose and energy storage, stored in live and human muscles, used in cells where large amounts of glucose storage would cause a problem. insoluble, easy to add and remove glucose subunits. made by animals and some fungi.
B. Carbohydrates & Lipids
20.Compare lipids to carbohydrates to determine which is more suitable for long term energy storage in humans.
2 reasons why. also mention glycogens role.
lipids are better for long term energy storage because:
1. the amount of energy released in cell respiration per gram of lipids is double that for carbs/protiens
2. Lipids add 1/6 as much to body mass as carbs thus fats are stored as pure droplets whereas 1g of glycogen (stored form of glucose-carb) is stored and associated with 2g of water— essential for active animals.
- fats are for energy storage: the energy is stored in speacilized groups of cells called adipose tissues located beneath the skin and around kidneys/ other organs
Glycogen is used for medium term storage:
glycogen is stored energy in the liver and muscles that is more readily avaliable than the energy stored in fats. Thus its good for quicker usage/short-medium term storage.
B. Carbohydrates & Lipids
21.Determine body mass index by calculation or use of a nomogram.
what is it and what is the formula
BMI used to identify weight problems- not a diagnostic tool.
BMI= mass in kg/(height in meters)^2
BMI unit= kg m^-2
nomogram: picture where you use a ruler to draw a line between height and weight to see the BMI
BMI vs status table will be given
B. Carbohydrates & Lipids
22 Outline the (2) types of fatty acids
Saturated?uns:structure/hydrogen/natural or synthesized/shape/density
Saturated:
refers to if more hydrogen atoms can be added to a fatty acid. a saturated fatty acid can’t add anymore hydrogens. an unsaturated fatty acid can add more hydrogens by getting rid of a double bond and replacing it with hydrogen.
Unsaturated
Cis-isomers
structure/positioning of hydrogen: C–C double bond with hydrogens on same side
natural or synthesized: common in nature
shape: all hydrogens on one side make it bent
density: loosley packed as its bent
Trans-isomers
structure/positioning of hydrogen: C–C double bond with hydrogens on opposite side
natural or synthesized: rare in nature- usually artificially produced
shape: linear- balance of hydrogen on either side
density: closley packed because linear
saturated= no double bonds
monounsaturated= 1 double bond
polyunsaturated= greater than one double bond
B. Carbohydrates & Lipids
23.Explain the process and component parts from which triglycerides are formed.
also know how to annotate it
A glycerol molecule and three fatty acids go through a condensation reaction. Three OH compounds are taken from the glycerol molecule, and one hydrogen atom is seperated from each OH compound on all of the fatty acids (3). Those react to form the product of 3 H2O. The oxygens left over on the fatty acids then bond with the carbon on the glycerol molecule. This is called an ester bond.
