IB ChemistryOpt B Human Biochemistry

B6 Hormones

B.6.1

• Outline the production and function of hormones in the body.

Explanation

 • There are two major

ways for the body to communicateo Nervous Systemo Endocrine System-

based on Hormones

Explanation• Hormones are chemical 

messengers. •  hormones have a variety of

structures including proteins, steroids, modified amino acids and fatty acids.

• They are secreted directly into the blood by endocrine glands in response to various stimuli

o This is because the glands do not have ducts

•  Hormones are transported using the blood stream

•  

Explanation

• Once the hormones are made, they only bring responses in cells that have receptors for them

• AKA TARGET CELLS

Explanation• Examples

o Antidiurectic Hormone (ADH) controls body water content

o aldosterone,  Steroid  regulates sodium potassium

balance in the bloodo estrogen,o progesteroneo testosterone,o insulin,o epinephrine (adrenaline)o thyroxine

FunctionsEndocrine Gland that Produces it

Hormone Function Target Cells

Pituitary Antidiurectic Hormone (ADH)

increases uptake of water; helps control osmotic potential of the blood

Kidney Tubules

Thyroid Gland Thyroxine stimulates growth and metabolism All cells

Adrenal Cortex Aldosterone Increases uptake Na+ by kidneys and helps control Na+ and K+ ratios in fluids; raises blood pressure

Kidney Tubules

Adrenal Medulla Adrenaline released during excitement/stress. Causes dilated pupils and an increase in blood glucose and increases blood supply in muscles

Most of body ex/ muscles, brain etc

FunctionsEndocrine Gland that Produces it

Hormone Function Target Cells

Pancreas Insulin decreases blood glucose level. made up of 2 poypeptide chains held together by disulfide bonds; regulates cellular intake of glucose from the blood 

all cells especially Liver!

Ovary Estrogen and Progesterone

Development of female secondary sexual characteristics; control of menstrual cycle, growth and development of placenta and fetus

Most parts of body especially Uterus  lining (during pregnancy)

Testes Testosterone Development of male secondary sexual characteristics

Many parts of Body

 

Sample QuestionsOutline the production and function of hormones in the body.           

Hormone Function

Antidiurectic Hormone (ADH)

increases uptake of water; helps control osmotic potential of the blood

Thyroxine stimulates growth and metabolism

Aldosterone Increases uptake Na+ by kidneys and helps control Na+ and K+ ratios in fluids; raises blood pressure

Adrenaline released during excitement/stress. Causes dilated pupils and an increase in blood glucose and increases blood supply in muscles

Insulin decreases blood glucose level. made up of 2 poypeptide chains held together by disulfide bonds; regulates cellular intake of glucose from the blood 

Estrogen and Progesterone

Development of female secondary sexual characteristics; control of menstrual cycle, growth and development of placenta and fetus

Testosterone Development of male secondary sexual characteristics

Sample Questions

Identify which of the two hormones is the female sex hormone and where in the human body it is produced. (2) Progesterone is the female sex hormone and is produced in the

ovaries.          

Sources• http://ibhumanbiochemistry.wikispaces.com/C.6.1• http://ibchem.com/IB/ibnotes/full/opc_htm/biochem.htm • Higher Level Chemistry Developed Specifically for the IB

Diploma by Catrin Brown and Mike Ford • IB Study Guides Chemistry by Geoffrey Neuss

        

B.6.2

• Compare the structures of cholesterol and the sex hormones.

Explanation

• Sex hormones all belong to a family of organic compounds called steroids (lipids)

• Consist of four contiguous carbon ringso Common steroid backbone

• Different steroids have different functional groups and side chains

Variable group

Explanation

• Cholesterol = most common steroid• Essential in cell tissue, brain and nervous tissue• Chain of alkanes on one ring with -OH (hydroxyl)

group on last ring

Male Sex Hormones

• Testosterone and Androsterone• Produced in testes• Characteristics:

Anabolic - encourage the growth of tissue, muscle and bone

Androgenic - Control the development and maintenance of masculine characteristics

Structure• Testosterone• Steroid backbone with one hydroxyl (-OH),

one ketone functional group (-C=O) and one alkene functional group (C=C)

Female Sex Hormones

• Oestradiol/estrogen and Progesterone • Produced in ovaries from puberty until

menopause• Responsible for sexual development and

menstrual reproductive cycles in women

Structure• Oestradiol/estrogen• Steroid backbone with two hydroxyl functional groups (-

OH) and benzene ring with alternating C=C bonds (aromatic compound)

• Progesterone• Steroid backbone with two ketone functional

groups (C=O) and one alkene functional group (C=C)

Sample QuestionsStudy the structure of the two sex hormones oestradiol and testosterone given in the Data Booklet. List the differences between the two structures.

Oestradiol Testosterone

Structural Differences

• 2 -OH functional groups• Benzene ring with alternating C=C bonds

• 1 -OH group• 1 -C=O (ketone) group• 1 -C=C (alkene) group

Sample Questions

7. The structures of two sex hormones, progesterone and testosterone, are shown in Table 22 of the Data Booklet.(a) State the names of two functional groups that are present in both hormones. (2) carbonyl/ketone, alkene

Sources

• http://ibhumanbiochemistry.wikispaces.com/C.6.2

• http://ibchem.com/IB/ibnotes/full/opc_htm/biochem.htm

B.6.3

• Describe the mode of action of oral contraceptives.

The Menstral Cycle and Pregnancy

• beginning of the menstrual cycleo pituitary gland releases follicle-stimulating hormone

(FSH)o FSH travels to the ovaries --> causes release of

estrogen prepares for release of an egg from the ovary prepares for build-up of the uterine wall to accept the

egg once it is fertilized

The Menstral Cycle and Pregnancy (cont.)

• after two weeks the luteinizing hormone (LH) o is released from the pituitary glando travels to the ovarieso releases progesterone which causes the egg to be

transported to the uteruso build up the uterine wall continues

• If the egg is fertilizedo egg embeds in the uterine wallo hormone levels rises dramatically

• If the egg is not fertilizedo hormone levels fallo menstruation begins

 

Oral Contraceptive aka The "Pill"

• consists of estrogen and progesterone hormones• the increase in the levels of these hormones

o prevents ovulationo inhibits pituitary gland from producing LH and FSH

stops the development of the utuerine linning --> prevents the attachment of the egg to the wall of the uterus

o thickens the mucus around the cervix preventing sperm from entering the uterus

 

Sample Questions

Outline the mode of action of oral contraceptives(3).  Answer:  Estrogen- and progesterone-containing oral contraceptives inhibit the release of LH releasing hormone, which suppresses levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH), therefore preventing follicular development and ovulation

Sources

• http://ibhumanbiochemistry.wikispaces.com/C.6.3•  http://ibchem.com/IB/ibnotes/full/opc_htm/biochem.htm • image:

http://health.nytimes.com/health/guides/specialtopic/birth-control-and-family-planning/background.html

• http://www.ncbi.nlm.nih.gov/pubmed/12308926

B.6.4

• Outline the Use and Abuse of Steroids

Uses

• Help a person to recuperate from a major illness

o Build muscle growth due to inactivity (AIDS and anemia)

Uses (for Women)

• Female Hormonesoex. estrogen, progesterone: hormone replacement therapy (HRT) for menopausal women, contraceptive pill

Uses (for Men)

• Male hormones (androgens) oex. testosterone: treatment of disorders of testes and breast cancer. 

oThese hormones are also known as anabolic steroids as they promote tissue growth especially muscles. 

o Increase weight in patients from weight loss

Abuses

• Main people who abuse steroids are athletes

o Change appearance of persono Build muscleo Increase athletic ability

Abuse in Steroids (side effects)

Liver tumors Mental state of abuser harmed

High blood pressure Skeletal growth

Fluid retention Heart disorders

Increase in bad cholesterol levels (LDL) Decrease in good cholesterol levels (HDL)

Kidney tumors Jaundice

Severe acne

Male Side Effects

No babies (Infertility) Frequent urination

Lowers the amount of sperm Develops breasts

Testicular shrinking Risk of Prostate cancer

Causes baldness

Female Side Effects

Facial Hair Cause of male baldness

Voice deepens Abnormal scheduling (menstrual cycle)

Sample Questions

• Are there any current treatment options for steroid abusers?

o No, there are no current treatments because no scientists are really looking into it. However, there are some scientists that have patients from steroid withdrawal and their idea treating steroid abuse is to educate everyone with the side effects and harms of steroids.

Sources

• http://www.drugabuse.gov/infofacts/steroids.html

• http://ibhumanbiochemistry.wikispaces.com/C.6.4

Sources

• http://www.drugabuse.gov/infofacts/steroids.html

• http://ibhumanbiochemistry.wikispaces.com/C.6.4