Unit 3: The Chemistry Of Life Flashcards
5 other elements needed in living organisms
Sulfur, calcium, phosphorous, iron, and sodium
Most frequently occurring chemical elements in living things
Carbon, hydrogen, oxygen, and nitrogen
One role for sulphur
Used in making of amino acids (tertiary structure of proteins with disulphide bridges)
One for role for calcium
Used in structure of bones and teeth. It’s ions are used in synaptic transmission
One role for phosphorous
Part of a DNA molecule. Used in phosphorylation. Used in ADP and ATP.
One role for iron
Used in hemoglobin
One role for sodium
Major part of action potentials
Oxygen is slightly
Negative
Outline the thermal property of water
Water has a high specific heat (it takes a lot of energy to raise one gram of the substance by one degree fare height). This means that it takes a lot higher or lower of a temperature to change the temperature of the water. This allows the water to be a coolant on a hot day. The water will stay cooler that the environment on a hit day. Additionally, it can be warm on a cold day.
Outline the cohesive properties of water
Water, due to the high electronegativity difference in oxygen and hydrogen, allows for the hydrogen bonding to occur. This creates dipole-dipole forces between water molecules and gives water it’s cohesive properties. This is useful in xylem and phloem of plants. For example, it allows water to be lifted up the plant despite gravity and transport nutrients.
Outline the solvent properties of water
Water is a polar molecule due to the high electronegativity difference between hydrogen and oxygen. This allows it to be a solvent for other polar molecules (like dissolves like; polar-polar and nonpolar-nonpolar). In water, ionic compounds dissociate. Because it is a good solvent, it is a good medium for chemical and metabolic reactions.
Explain water’s use in living organisms as a coolant
Due to the thermal properties of water, water is able to be a good coolant. It can maintain a lower temperature I a hit environment because it has a high specific heat (takes a lot of energy to change temperature of water). Sweat is an example of this in nature.
Explain water’s use in living organisms as a medium for metabolic reactions
Because water is a good solvent, it is a good medium for metabolic reactions. Ionic compounds dissociate into ions in it and the particles are able to easily collide. This allows for reactions to occur in the body and in labs.
Explain water’s use in living organisms as a medium for transport medium
Water has cohesive properties due to its hydrogen bonds. This allows for water to love against gravity in plants, it can carry nutrients to all parts of the plants in the phloem and xylem because of this.
Distinguish between organic and inorganic compounds
Organic compounds contain carbon and inorganic do not
Exceptions to organic compounds containing compounds
Carbonates, hydrogen carbonates, and carbon dioxide
Function of glucose in animals
Small molecules that are easily broken down for energy
Function of lactose in animals
Easily broken down into monosaccharide
Function of glycogen in animals
Insoluble. Used for storage
Function of fructose in plants
Small molecule easily broken down for energy in cell respiration
Function in sucrose in plants
Soluble, but up reactive so it can be transported throughout plant
Function of cellulose
Insoluble energy molecule
Outline the role of condensation and hydrolysis in e relationship between amino acids
Condensation (adding water) reactions are used in order to create chains of monomers. In amino acids two amino acids (monomers) joined other form a dipeptide. Hydrolysis reactions remove a water and break the compound into lower forms such as monomers.
3 functions of lipids
Buoyancy, insulation, key component in plasma membranes, shock absorber (protection), hormones, structure
Carbs or lipids? Short terms energy, quickly accessed, easy transportation, soluble, low energy per unit, small
Carbohydrates
Outline DNA nucleotide structure in terms of sugar (deoxyribose), base, and phosphate.
A DNA nucleotide is composed of deoxyribose (5 carbon) sugar, a base (adenine, guanine, cytosine, or thymine), and a phosphate group
State the names I’d the four bases in DNA.
Adenine, guanine, cytosine, thymine
Outline how DNA nucleotides are linked together by covalent binds into a single strand
Covalent bonds link the 3’ and 5’ ends of the sugar and create the sugar-phosphate backbone of DNA. This creates a single strand.
Define enzyme
Proteins (globular) that act as chemical reactions
Define active site
Region on surface of the enzyme where the substrate bonds (this is what is responsible for catalysing reactions with substrates)
List three examples of monossaccarides
Glucose, galactose, fructose
List three examples of disaccharides
Maltose, lactose, sucrose
List three examples of polysaccharides
Starch, glycogen, cellulose
Explain enzyme-substrate specificity
According to the lock and key theory, enzymes and substrates are specific to one another, this suggests that one enzyme active site can inky accept one substrate that will fit precisely into its active site
Explain the effects if temperature on enzyme activity
Enzymes have an optimum temperature at which they function. If the temperature decreases, the enzyme activity will decrease, but it will not denature the enzyme. As temperature increases so does rate of reaction (enzyme activity) up to a point, and following that point, the rate decreases and will cease due to the denaturation of the enzymes.
Explain the effects of pH on enzyme activity
Enzymes have optimum pH at which they operate. As it varies from this direction, the enzyme activity will decrease
Explain the effects of substrate concentration on enzyme activity
As substrate concentration increases the rate of reaction will too because more active sites are being occupied during the chemical reaction. Once the substrate gets to a certain point, reaction rate will stay the same (because all of the active sites will be occupied and there will be excess).
Define denaturation
Denaturation is the changing of the structure of an enzyme so it can no longer function. This may occur as the result of temperature being increased too high.
Explain the use of lactase in the production of lactose-free milk
He enzyme lactase breaks down the sugar lactose into glucose and/ or galactose. Som people do not have this enzyme (lactose intolerant). This is fixed in lactose-free milk by doing one of two things. The first is adding lactase to the milk. The second is to pass the milk over a material that contains lactase (so that the milk ends up not containing lactase).
Primary structure
The primary structure of a protein is it’s amino acid sequence. This amino acid sequence is determined by the base sequence of the gene which codes for the protein
Secondary structure
Secondary structures have a-helices and b-pleated sheets. These form as a result of hydrogen bonds between the peptide groups of the main chain. Therefore. Proteins that contain secondary structures will have region that are cylindrical (a-helices) and/or regions that are planar (b-pleated sheets)
Tertiary structure
The tertiary structure of a protein is it’s three-dimensional conformation which occurs as. Result of the protein folding. This folding is stabilised by hydrogen bonds, hydrophobic interactions, ionic bonds and disulphide bridges. These intermolecular bonds form between the R groups of different amino acids.
Quaternary structure
A quaternary structure is formed when two or more polypeptide chains associate to form a single protein. An example is haemoglobin which consists of four polypeptide chains. In some cases, some proteins can have a non-polypeptide structure called a prosthetic group. These proteins are called conjugated proteins. The haem group in haemoglobin is a prosthetic group.
