The most common phase transition to ice Ih occurs when liquid water is cooled below 0°C. As a naturally occurring crystalline solid with an ordered structure, ice is considered a mineral. It possesses a regular crystalline structure based on the molecule of water, which consists of a single oxygen atom covalently bonded to two hydrogen atoms, or H-O-H. Many of the physical properties of water and ice are controlled by the formation of hydrogen bonds between adjacent oxygen and hydrogen atoms. It is a weak bond, but is decisive in controlling the structure of both water and ice.
Enzymes are proteins that are used to speed up these reactions without being consumed by them. The activity of these enzymes can be altered by changing their environments, such as enzyme specificity (speed only a reaction that contains their substrate), increasing and decreasing temperature, concentration level, or adjusting the pH level. Catalase is a catalyst that digests potent hydrogen peroxide and converts it into H2O and O. It is due to this hydrogen peroxide digesting ability that we used catalase in this experiment. To record the role that environment plays in the reaction of an enzyme, we exposed the enzyme to various changes in temperature, concentration, and pH.
1 mark AND Extreme pH denatures the enzyme, altering the shape of the active site and preventing the enzyme and substrate forming a complex, thereby decreasing the rate of the reactions. This is seen in a decrease in the amount of oxygen being produced. 1 mark c. This pH will need to be read from the graph 1 mark AND Optimum pH 1 mark Question 2 a. Any 2 of the following The volume the pH solution The volume of peroxide The surface area of the liver cube The same size test tube 1 mark b. The pH 1 mark c. Treatment group refers to all groups which are being manipulated or varied during an experiment.
The term Cp is the specific heat of the material (at constant atmospheric pressure). Different materials have different specific heat values. The units of specific heat are : Joules/gram deg – C. In this lab we will find the specific heat value of Zinc and compare it to accepted values.This will do by heating a mass of Zinc up to the temperature of boiling water and placing the hot metal into a cup of cold water. The thermal energy that the zinc loses goes into heating up the water in the cup. By knowing the starting temperatures and the final temperature of the water and the zinc, the specific heat of Zinc may be easily obtained.
Deficiency of the enzyme lactase (common in adult mammals) prevents cleavage of the glycosidic link in lactose during digestion. Instead, anaerobic bacteria in the large intestine ferment this sugar, producing gas, abdominal discomfort and bloating. What gas is formed and what metabolic byproduct(s) also are released into the large intestine? b) Briefly describe the differences between the polysaccharides….. i) amylopectin and glycogen ii) amylose and chitin 2. (10 points) The catabolic cycle called glycolysis is the most universal energy-producing metabolic pathway for organisms that live on or near the earth’s surface.
The reaction can only take place if the colliding particles possess enough energy to break and make new bonds; this is known as the activation energy. Only a fraction of particles in this reaction will have energy greater than the activation energy. This is given by the expression e-EA/RT, e is the exponential function, R is the gas constant and T is the absolute temperature. This means at a specified temperature the reaction rate depends on how many particles have the activation energy. K is known as the rate constant for the rate of reaction if this is dependent on the particles that have the
Effect of Enzyme Activity on Temperature Aim: The aim of this experiment is to investigate how effectively the enzyme amylase breaks down starch at different temperatures Research Question: How does the increase in temperature affect the time taken for amylase to breakdown 2ml of starch? Purpose: Background Information: Enzymes are biological catalysts that comprise the largest and most highly specialized class of protein molecules. Enzymes act as catalysts to increase the rates of chemical reactions. A fundamental property of enzymes is their specificity. Various enzymes have unique shape and chemical composition that creates a site, called and active site.
This is where the reactions occurs. From there the enzyme breaks the bond in the substrate and the enzyme can continue to repeat the process. Catalase is an enzyme found in almost all living organisms. In the human body it is an enzyme that is produced by our liver to break down hydrogen peroxide into water and oxygen. Even though hydrogen peroxide is naturally produced by our body as a byproduct of our metabolic process, it is very toxic to our body.
Amino acids are considered to be strong acids because they have a strong charge on the amino group. This strong charge on the amino group creates an affinity for carboxylic acids to lose a proton. The isoelectric point, pI, is the pH of an aqueous solution of an amino acid at which the molecules have no net charge. In other words, the positively charged groups are exactly balanced by the negatively charged groups. When this dissolved amino acid is titrated with an acid it reacts like a base, and when titrated with base it acts like an acid.
Si, P, S and Cl are increasingly electronegative. They cannot form oxide ions from oxygen at all, so they behave as acids. The trend is from strongly basic oxides on the left-hand side to strongly acidic ones on the right, via an amphoteric oxide (aluminium oxide) in the middle. In addition, when going across the period 3 the acid-base nature of the oxides change from base to amphoteric and finally to become acid. This is because the less electronegative sodium has a weak Na-O bond and the oxygen is more easily given up to reacts with H+.