3
4
Number of drinks
0
0
3
2
BAC at start of hour
0.00
0.00
0.00
0.05
BAC from table
0.00
0.00
0.07
0.05
BAC (start + table)
0.00
0.00
0.07
0.10
Alcohol broken down
0.00
0.00
–0.02
–0.02
BAC at end of hour
0.00
0.00
0.05
0.08
Figure 5.6. BAC over time for Guest 4.
158
Guest 5 is a 140-pound male:
Hour 1
2
3
4
Number of drinks
3
2
1
0
BAC at start of hour
0.00
0.06
0.09
0.10
BAC from table
0.08
0.05
0.03
0.00
BAC (start + table)
0.08
0.11
0.12
0.10
Alcohol broken down
–0.02
–0.02
–0.02
–0.02
BAC at end of hour
0.06
0.09
0.10
0.08
Figure 5.7. BAC over time for Guest 5.
159
Student Lesson 5
Understanding Alcohol: Investigations into Biology and Behavior Guest 6 is a 220-pound male:
Hour 1
2
3
4
Number of drinks
3
2
1
0
BAC at start of hour
0.00
0.03
0.04
0.04
BAC from table
0.05
0.03
0.02
0.00
BAC (start + table)
0.05
0.06
0.06
0.04
Alcohol broken down
–0.02
–0.02
–0.02
–0.02
BAC at end of hour
0.03
0.04
0.04
0.02
Figure 5.8. BAC over time for Guest 6.
160
10. Conclude the activity by asking students to respond to the following questions.
• Which individuals could drive home legally?
If the legal BAC limit in the state is 0.08 percent, Guests 2, 3, and 6
would be below the legal limit for intoxication and able to drive home legally. Note that if an individual’s BAC is right at the legal limit (BAC = 0.08 in this case), it is not legal for that individual to drive a car.
Although these individuals could legally drive, they might not be safe drivers. In the following activity, students will learn more about how even low BACs can impair judgment, coordination, and
reflexes.
• What factors described in this activity affected the party guests’
BAC levels?
Students should recognize that number of drinks, pattern of drinking, gender, and body weight all influence a person’s BAC.
• Why, on average, is a larger person affected less by a given amount of alcohol than a smaller person?
A larger person has more body water for the alcohol to be distributed in. This means that a given amount of alcohol will reach a lower BAC in a large person than a smaller person.
• Why, on average, are females more affected by drinking the same amount of alcohol as males?
Females tend to be affected more by a given amount of alcohol than males for two reasons. First, they tend to be smaller than their male counterparts and second, they tend to have more body fat than males do, which has the effect of reducing the amount of body water in which to distribute the alcohol.
• How does the pattern of drinking relate to an individual’s BAC?
A person’s BAC is affected mainly by how much alcohol he or she drinks and over what period of time the drinking occurs. Alcohol metabolism occurs at a constant rate. If the rate of alcohol consumption is faster than the body’s metabolism rate, then the BAC will increase.
161
Student Lesson 5
Understanding Alcohol: Investigations into Biology and Behavior
• Are there differences in how fast alcohol breaks down in the body among different individuals?
Students should notice that in this activity, the BAC always decreases by approximately 0.02 percent per hour for all individuals. In reality, metabolism rates can vary somewhat among individuals. The important point here is that when a person drinks alcohol, it is broken down at a constant rate, regardless of how quickly or slowly the person drinks.
• Do you think that each of the individuals whose behavior was modeled in this activity would have reached the same conclusions as you did about who should drive from the party?
The guests attending the party in this activity would not have access to information about their BACs. Therefore, it is likely that some of them would have judged themselves fit to drive, even though their BAC exceeded the legal limit.
• Are there any factors not taken into account during this activity that could influence an individual’s BAC?
Student responses will vary. Accept all reasonable responses and list them on the board. Direct their attention to factors such as the amount and type of food in the stomach, body type (amount of body fat), and genetic factors.
11. Ask students to keep their copies of Masters 5.1 and 5.2 for use in the next activity.
Optional Activity
Content Standard A:
Identify questions that
1. Give students an opportunity to ask their own questions about can be answered
how an individual’s BAC is affected by drinking alcohol. For convenience, students can work in their same teams to decide on a through scientific
question they want to investigate. Remind students to ask a ques-investigation.
tion that can be answered given the information found in Masters 5.1 and 5.2. Some questions that students may investigate include Content Standard A:
the following:
Design and conduct a
scientific investigation.
• Can a person who weighs 200 pounds drink twice as much as a person who weighs 100 pounds and have the same BAC?
• If a person has a BAC of 0.08 and stops drinking, how long will that person have to wait before their BAC drops to zero?
162
• Consider someone attending a party that lasts for 4 hours. The person consumes 4 drinks during the party. How will their BAC at the end of the party vary if they drink all 4 four drinks during the first hour, drink 1 drink each hour, or drink all 4 drinks during the last hour?
Assessment:
This part of the activity
Asking an appropriate question might be difficult for some students.
enables you to assess
Explain that they should try to keep all variables constant, except for students’ abilities to
the one that they are investigating. Circulate around the room and identify questions that
ask them to explain how they are answering their question. If they have difficulty making proper comparisons, guide them with ques-can be answered
tions that will help them refine their question or the way they are through scientific
conducting their analysis.
investigation. It also
provides assessment
2. After teams finish analyzing their question, ask them to present opportunities relating
their results to the class. Encourage each member of the class to to methods of analysis
participate in the presentation by discussing a specific aspect of the work, such as framing the question, performing the calcula-and drawing of conclu-
tions, or stating the conclusions. Ask other members of the class if sions.
they agree or disagree with the conclusions.
Activity 2: Alcohol and Driving Behavior
This activity requires the use of computers with access to the Internet and a sound card. If this is not possible, give each
student team a copy of Master 5.4, Progressive Effects of Alcohol, and proceed with this activity starting with Step 8.
1. Introduce the activity by explaining to the class that they will watch two brief driving simulations. The simulations show the view as the driver would see things.
2. Divide the class into teams of two to three students who will work at one computer. Log onto the Web site
http://science.education.nih.gov/supplements/alcohol/student and click on “Lesson 5—Alcohol and Driving: When to Say No.”
Teacher note
This activity is designed for students to work at a computer in small teams.
This approach stimulates interaction and discussion among students. You may, however, need to modify the size of the groups depending on the number of computers available. For alternate strategies, see Using the Web Site, on page 19.
163
Student Lesson 5
Understanding Alcohol: Investigations into Biology and Behavior 3. Instruct students to watch Simulation A and Simulation B and to record the differences they observe between the two drivers.
Students will not know at the beginning which simulation represents which driver. However, they should record their observations about each simulation. Students may need to watch each simulation a few times.
4. After students have viewed the simulations and recorded their observations, discuss their findings and record their observations on the board. The major differences are listed below:
Simulation A (intoxicated)
Simulation B (sober)
Staggers while walking to car
Walks in a straight line to car
Content Standard A:
Has blurred vision
Has clear vision
Think critically and log-
Does not look both ways
Looks both ways before crossing
ically to make the rela-
before crossing the street
the street
tionships between
Does not fasten seat belt
Does fasten seat belt
evidence and explana-
Has trouble putting key in
Puts key in ignition easily
tions.
ignition
Exceeds speed limit
Does not exceed speed limit
Does not always stay in
Stays in correct lane
correct lane
Drives using one hand
Drives using both hands
Runs through stop signs
Stops smoothly at stop signs
Does not stop for pedestrian
Stops to allow pedestrian to
cross street
Does not use turn signals
Does use turn signals
Hits the trash can in driveway
Parks car without hitting trash
can
Students may notice other minor differences, but the ones listed above are the primary ones.
5. One simulation portrays a sober driver and the other portrays an intoxicated driver. Ask students which simulation shows the intoxicated individual.
Students will respond correctly that Simulation A shows the intoxicated driver.
6. Ask students what they think the BAC of the driver in Simulation A was. Display a transparency of Master 5.4, Progressive Effects of
Alcohol. This chart depicts the escalating impairments that happen as increasing amounts of alcohol are consumed. Explain that impairments associated with low BACs still apply at higher BACs.
164
7. Ask students to provide reasons for their BAC estimates.
Students should estimate a BAC for the intoxicated driver based on information in Master 5.4 and on what they observed in the simulation. Because students know that the driver is intoxicated, they will estimate BACs of 0.08 and higher. Students might say that the BAC
could be as high as 0.21 to 0.30 because the person staggered when walking. If the BAC is in this range, in addition to the more severe impairments of reaction time and lack of balance, the driver would also display impaired alertness, judgment, depth perception, reasoning skills, and coordination. Each of these impairments would make this person a hazardous driver.
8. Ask students to get out their copies of Master 5.2, Drinking Pat-
terns for Party Guests, from Activity 1 in this lesson. Ask them to examine the data for each of the party guests they evaluated. Using Master 5.4, Progressive Effects of Alcohol, instruct the class to estimate how each individual’s BAC would affect his or her ability to drive a car. Revisit the question of whether or not each individual should drive home. Students can write their responses on the back of Master 5.2.
Students should compare the BAC of each individual with the table.
They should list activities that are impaired in individuals who have a BAC in that range.
You will notice that the chart on Master 5.4 is depicted as a continuum and that there are no distinct cut-off points between impairments at adjacent BAC ranges. This is intended to convey the idea that impairments exist in varying degrees as opposed to simply being present or absent. This depiction is also consistent with human variation; that is, two people may be affected slightly differently from each other at a given BAC.
9. Give students the opportunity to share with the class their conclusions about each of the party guests and the impairments that would affect their driving.
Guest 1 has a BAC of 0.08 at the end of the party. Students may respond that she should exhibit impairments in alertness, judgment, depth perception, and visual tracking. Most will agree that she should not be behind the wheel.
165
Student Lesson 5
Understanding Alcohol: Investigations into Biology and Behavior Guest 2 has a BAC of 0.04 at the end of the party. Students may respond that even though he has a BAC below the legal limit for driving, he is still affected by the alcohol. He may be less alert and less coordinated and make poorer judgments than if he hadn’t drunk Assessment:
any alcohol.
If you wish to use this
Similar types of observations can be made for the other four party question as a more
guests. Some students may conclude that it may not be a good idea formal opportunity to
for any of the party guests to drive a car.
evaluate students’
understanding, ask
10. Ask students to consider the question, Does a BAC below the legal them to write their
limit mean that it is safe for an individual to drive a car?
answers to this ques-
Even though some individuals have BACs that are below the legal tion. You may then
limit for driving, it may not be safe for them to operate a car. This is review the responses
an important point for students to understand. A BAC below the from each student.
legal limit does not mean that a person’s mental and physical skills Asking students to
are not impaired. In fact, there is no one particular BAC where haz-write their answers
ardous driving begins. Even one drink can cause impairment. This before sharing them
helps explain why different states and different countries set different with the class allows
legal limits for drinking and driving.
them to organize their
thoughts and reflect
on what they have
learned.
166
Lesson 5 Organizer
Activity 1: Patterns of Drinking
What the Teacher Does
Procedure Reference
Ask the class if two people attend a party and drink the same
Page 151
amount of alcohol, will they be affected in the same way?
Step 1
Ask students to recall information they learned in previous
Pages 151–152
lessons.
Step 2
• What factors influence how different people respond
to alcohol?
• Where does alcohol go in the body?
• Where is alcohol broken down?
Help the class understand how to use Master 5.1, Blood
Pages 152–153
Alcohol Concentration Tables.
Steps 3 and 4
• Make sure that the students understand how metabo-
lism reduces BACs.
Divide the class into teams and make sure they know how to
Page 153
• determine BAC levels for fictitious individuals attending
Steps 5 and 6
a party.
• determine if those individuals can legally drive a car.
Pass out to each team a copy of Master 5.2, Drinking Pat-
Pages 153–154
terns for Party Guests.
Step 7
Have students graph the BACs over time for each guest
Page 154
using Master 5.3, Blood Alcohol Concentration Graph
Step 8
Template.
= Involves copying
= Involves using
= Involves using
a master.
a transparency.
the Internet.
167
Student Lesson 5
Understanding Alcohol: Investigations into Biology and Behavior Have student teams share their results with the class using a
Pages
transparency of Master 5.3, Blood Alcohol Concentration
155–160
Graph Template.
Step 9
Summarize results from the activity. Ask the class,
Pages 161–162
• Which individuals could drive home legally?
Step 10
• What factors affected the party guests’ BAC levels?
• Why is a larger person affected less by a given amount
of alcohol than a smaller person?
• Why are females more affected by drinking the same
amount of alcohol as males?
• How does the pattern of drinking relate to an individ-
ual’s BAC?
• Are there differences in how fast alcohol breaks down
in the body among different individuals?
• Do you think that the individuals whose behavior was
modeled in this activity would have reached the same
conclusions as you did about who should drive from
the party?
• Are there factors not taken into account during this
activity that could influence an individual’s BAC?
Instruct students to keep their copies of Masters 5.1 and
Page 162
5.2 for use in the next activity.
Step 11
Activity 2: Alcohol and Driving Behavior
What the Teacher Does
Procedure Reference
Explain to the class that they will watch two short driving
Page 163
simulations.
Step 1
Divide the class into student teams and have them log onto
Page 163
the Web site. Have the students click on “Lesson 5—Alcohol
Step 2
and Driving: When to Say No.”
168
Instruct students to watch each simulation and record their
Page 164
observations.
Step 3
Reconvene the class, discuss the students’ findings, and
Page 164
record their observations on the board.
Step 4
Ask the students which simulation portrayed the intoxicated
Page 164
driver.
Step 5
Display a transparency of Master 5.4, Progressive Effects of Pages 164–165
Alcohol, give each team a copy, and ask the class to esti-Steps 6 and 7
mate the BAC of the intoxicated driver.
Have students retrieve their results from Activity 1 and ask
Page 165
them to consider how alcohol impaired each of the party
Step 8
guests.
Have students share their conclusions with the class.
Pages 165–166
Step 9
Discuss whether a BAC below the legal limit means that it
Page 166
is safe for an individual to drive a car.
Step 10
169
Student Lesson 5
Blood Alcohol Concentration Tables*
For Women
Body weight in pounds
Drinks
100 120
140 160 180 200 220 240
per hour
1 0.05 0.04 0.03
0.03 0.03 0.02 0.02 0.02
2 0.09
0.08
0.07
0.06
0.05
0.05
0.04 0.04
3
0.14
0.11
0.10
0.09
0.08
0.07
0.06
0.06
4
0.18
0.15
0.13
0.11
0.10
0.09
0.08
0.08
5
0.23
0.19
0.16
0.14
0.13
0.11
0.10
0.09
6
0.27
0.23
0.19
0.17
0.15
0.14
0.12
0.11
7
0.32
0.27
0.23
0.20
0.18
0.16
0.14
0.13
8
0.36
0.30
0.26
0.23
0.20
0.18
0.17
0.15
9
0.41
0.34
0.29
0.26
0.23
0.20
0.19
0.17
10