Homework Help for Biology

1. A polysaccharide of unknown structure was isolated, subjected to exhaustive methylation, and hydrolyzed. Analysis of the products revealed three methylated sugars: 2,3,4-tri-O-methyl-D-Glucose, 2,4-di-O-methyl-D-glucose and 2,3,4,6-tetra-O-methyl-D-glucose, in the ratio 20:1:1. What is the structure of the polysaccharide?

1. Metabolic alkalosis is a condition in which the blood pH is higher than its normal value of 7.40 and can be caused, among other reasons, by an increase in [HCO3-]. If a patient has a following blood values, pH= 7.45, [CO2]=1.25 mM, What is the [HCO3-]? The pk1 for the bicarbonate/carbonic acid system is 6.1. How does the calculated Value of bicarbonate compare with the normal value?

1. When glucose is added and stirred, the water feels cooler. Why?

1. When a piece of paper is wet with water, it tears off easily. But the same paper if soaked in oil doesn’t lose strength. Why?

1. Why does ice melt when salt is sprinkled on it?

1. In order to have 99% of the glycine in its –NH3+ form, what must the numerical relation be between the pH of the solution and the pKa of the amino group of glycine?

1. How much 5 m KOH must be added to 1.0 L of 0.1 M glycine at pH 9.0 to bring its pH to exactly 10.0?

1. In a 0.1 m solution of glycine at pH 9.0. what fraction of glycine has its amino group in the –NH3+ form?

1. In what pH range can glycine be used as an effective buffer due to its amino groups?

1. The amino acid glycine is often used as the main ingredient of a buffer in biochemical experiments. The amino group of glycine, which has a pKa of 9.6, can exist either in the protonated form(-NH3+) or as the free base(-NH2) because of the reversible equilibrium

1. In a hospital laboratory, a 10.0mL sample of gastric juice, obtained several hours after a meal, was titrated with 0.1M NaOH to neutrality; 2mL of NaOH was required. The patient’s  stomach  contained no ingested food or drink, thus assume that no buffers were present. What was the pH of the gastric juice?

Which animal dies by drinking water?

Describe the growth in bacteria 

what is biology?

Research, create, and record information on a career related to (1) one of the 4 strands covered (Biochemistry, Metabolic Processes, Molecular Genetics, Homeostasis, Population Dynamics). Select (1) one career of your choice, but it must relate to the units of study covered in the Grade 12 University Biology course.

1. Biochemistry

2. Metabolic Processes

3. Molecular Genetics

4. Homeostasis

5. Population Dynamics

You will include the following information:

1. Job title

2. Job description

3. Educational Requirements (high school pathway & post-secondary requirements)

4. Skills required

5. How it relates to a specific strand of SBI4U

Research: Using the computer research the above information on a career of your choice. Use the information sheet provided to write down all your information. You are to submit this sheet at the end of the period.

Career/Job Title

Job Description

Educational Requirements

(highschool pathway & post- secondary requirements)

Skills Required

Grade 12 University Biology Strand in which it relates to?

How does it relate to this specific strand? Be specific in your answer.