Caffeine Half-Life Worksheet printable pdf download

Caffeine Half-Life Worksheet

Name: ________________

Block: _____

Half-life in hours = the time required to metabolize ½ the amount of caffeine

Directions: In each of the following problems, calculate the half-life of caffeine in the person’s system.

Show your work.

1. Ellen, a smoker (3.5 hours needed to metabolize caffeine), drank a Starbucks Grande (320 mg/16 oz.)

at 7:30am before school, had a Hershey’s chocolate bar (9 mg/1.55 oz.) and a 20 oz. Diet Coke (78

mg) with her lunch. After school, before practice, she had a Spike Shooter energy drink (300 mg/8.4

oz.). Ellen’s body is accustomed to her caffeine intake so she feels a negligible effect from caffeine

at 90 mg. How long will it take for Ellen’s body to metabolize the caffeine to 90 mg?

How long would it take Ellen’s body to metabolize the caffeine if:

She was not a smoker? (5-6 hours needed to metabolize caffeine)

She was an oral contraceptive user? (12 hours needed to metabolize caffeine)

Garth, a college student, loves Rip It and believes he studies better when he drinks it. One evening,

during his study time, he consumed four cans of Rip It (100 mg/per 8 oz. can) and chewed 2 sticks of

Jolt Caffeinated gum (33 mg/per stick). Since he has developed a tolerance to caffeine, assume that

his caffeine level of negligible effect is 60 mg. How long would Garth’s liver take to metabolize the

caffeine so that he has no effect (<60 mg) from his caffeine ingestion?

Billy, a middle school student, was up late last night playing X-Box. Before dawn, he ate 3 cups of

Ben and Jerry’s Coffee Heath Bar Crunch Ice Cream (84 mg/per cup). This morning for breakfast,

he drank a Red Bull (80 mg/8.3 oz.) and ate 2 oz. of Jelly Belly Extreme Sports Beans (50 mg/1 oz.

bag). On the bus, Billy ate a Hershey’s Special Dark Chocolate Bar (31 mg/1.45 oz.) and drank

chocolate milk (5 mg). If this is all the caffeine he consumes today, how long will it take for Billy’s

caffeine level to hall below 20 mg?

Beth is in her second trimester of pregnancy (10-18 hours needed to metabolize caffeine). She’s

careful about avoiding caffeine, but didn’t realize there was caffeine in Sunkist Orange Soda and

Haagen-Dazs Coffee Light Ice Cream. Today at lunch, she had an orange soda (41 mg/12 oz.) and a

cup of the ice cream (58 mg/8 oz.). Beth had a headache and took 2 Anacin Maximum Strength

tablets (32 mg/per tablet) her friend gave her. How long will it take for her caffeine level to return

to zero?

Caffeine Half-Life Worksheet