COMMUNICATING23.Use Internet resources to find the chemical
make-up of a heme, a key component of
hemoglobin.
24.Create a chart to summarize the bonds between
atoms studied in biological systems.
25.Make a series of diagrams (similar to a cartoon
strip) showing how buffers help maintain a
near-constant environment in the cell.
26.Draw diagrams of two amino acids. Circle the
R-group for each. Make a generalized diagram
for all amino acids.27.Some molecules can exist in different
configurations that are important in a variety
of metabolic processes. For example, glucose,
a common monosaccharide, occurs in open
chain and ring-shaped forms. The flexible
nature of the chain form allows glucose to
twist into a ring shape. The ring structure
forms when the carbonyl functional group
reacts with one of the alcohol groups within a
single glucose molecule. In this reaction, one
hydrogen atom is transferred from an alcohol
group to the carbonyl group. This process32 MHR • Unit 1 Metabolic Processes
20.Scientists must pay close attention to the
concentration of solutions when reproducing
conditions for living systems in an experiment.
To make 1 L of a 1 mol/L solution of glucose,
1 mol of glucose (180.18 g) is added to a 1 L
volumetric flask. Some distilled water is added
and the contents swirled to dissolve the
glucose. More distilled water is added up to
the etch line of the volumetric flask.
(a)What mass of glucose (in grams) should be
used to make a 0.5 mol/L solution using the
same volumetric flask?
(b)What mass of glucose (in grams) should be
used to make a 0.5 mol/L solution using a
500 mL flask?
(c)What mass of glucose (in grams) should be
used to make a 0.1 mol/L solution using a
500 mL flask?
21.Cellular respiration uses O 2 and releases CO 2.
Released into water, CO 2 forms carbonic acid
(H 2 CO 3 ), which dissociates to produce a
hydrogen (hydronium) ion. To determine thequantity of CO 2 produced by germinating
seeds, a titration can be performed that
neutralizes the hydronium ions produced.
A 0.01 mol/L solution of NaOH is used to
neutralize the acid. In one trial, 9.7 mL of
NaOH was added to neutralize the water
containing germinating seeds. Outline how to
set up a control for this experiment and the
results you would expect.
22.Dialysis tubing is a cellulose material used to
make model cells for experiments in osmosis
and diffusion. These model cells do not use
living cell membranes. A student made a
model cell by pouring distilled water into some
dialysis tubing. The student placed the model
cell in a salt solution and waited 10 minutes.
The cell was then removed from the salt
solution and the contents poured into a test
tube. The student added silver nitrate to the
test tube and a white precipitate formed. This
indicated that chloride ions had entered the
cell. Would this be true for living cell
membranes? Design an experiment to test this.19.Copy and label this diagram of condensation
synthesis and hydrolysis.
a.d.c.b.H OH H OH
H OH
H OH
H OH
HO 2 HO 2INQUIRY