AP Biology

Agenda for 3/19 Cell Communication Booklet Review using PPT “My Dog is Broken” Organize work and concept mapping

That’s life- Why you and your iPod must die ~ due Monday

Behavior booklet due Wednesday

Mini-test _____– Development, Nervous System and Cell Communication

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Agenda for 3/20 Complete Cell Communication Booklet

Review My Dog is Broken - Case Study Cell Signaling Project Assignment

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A. Cell Signaling Yeast cells

Identify their mates by cell signaling factor

Receptor Exchange of

mating factors. Each cell type

secretes a mating factor that binds to receptors on the other cell

type.

1

Mating. Binding of the factors to

    receptors induces changes      in the cells that

    lead to their     fusion.

New a/ cell. The nucleus of the fused cell

includes all the genes from the a and cells.

2

3

factorYeast cell,mating type a

Yeast cell,mating type

a/

a

a

Figure 11.2

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Water and Mineral Absorption –Water Transport in Roots

Apoplastic or symplastic Until the

endodermis Is reached!!

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Translocation of Phloem Sap-Loading of Sugars

Flow through the symplast or apoplast in mesophyll cells into sieve-tube members

Active co-transport of sucrose with H+

Proton pump

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Cell Junctions

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Regulation & Communication Animals rely on 2 systems for regulation

endocrine system system of ductless glands

secrete chemical signals directly into blood chemical travels to target tissue target cells have receptor proteins slow, long-lasting response

nervous system system of neurons

transmits “electrical” signal & release neurotransmitters to target tissue

fast, short-lasting response

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Short Distance w/chemical messengers

axon

endocrine gland

receptor proteins

target cell

Neurotransmitters released by neurons Hormones release by endocrine glands

receptor proteins

hormone carried by blood

neurotransmitter

Lock & Keysystem

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Paracrine Signaling on your tongue

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Nitric Oxide Signaling in the Penis and Heart

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Prostaglandin Signaling by Sperm in the Uterine Cells

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AP Biology 2007-2008

Endocrine SystemHormones

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Why are hormones needed? chemical messages from one

body part to another communication needed to

coordinate whole body daily homeostasis & regulation of

large scale changes solute levels in blood

glucose, Ca++, salts, etc. metabolism growth development maturation reproduction

Regulation

growth hormones

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Lipid-based hormones hydrophobic & lipid-soluble

diffuse across cell membrane & enter cells bind to receptor proteins in cytoplasm & nucleus bind to DNA as transcription factors

turn on genes

Structure Steroids- modified cholesterol

testosterone-muscles, bone mass, body hair, testis and prostate development

estrogen – female development, menstrual cycle control (maintains lining of uterus)

Aldosterone – controls sodium and potassium balance and blood pressure

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Steroid Hormone

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nucleus

target cell

DNAmRNA

protein

blood

proteincarrier

S

S

S

S

Action of lipid (steroid) hormones

binds to receptor protein

cytoplasm

becomes transcription factor

ex: secreted protein = growth factor (hair, bone, muscle, gametes)

2

4

6

cross cell membrane

1

steroid hormone

mRNA read by ribosome5

plasma membrane

protein secreted7

3

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Protein Based Hormones hydrophilic & not lipid soluble

can’t diffuse across cell membrane bind to receptor proteins in cell membrane trigger secondary messenger pathway activate internal cellular response

enzyme action, uptake or secretion of molecules…

Structure polypeptides

small proteins: insulin, ADH glycoproteins

large proteins + carbohydrate: FSH, LH Amines-modified amino acids:

epinephrine – see example

melatonin – regulates sleep/wake cycle by lowering body temperature and causing drowsiness

insulin

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Action of protein hormones

activatesenzyme

activatesenzyme

activates enzyme

ATP

produces an action

P1

2

3

cytoplasm

receptor protein

response

signal

secondarymessengersystem

signal-transduction pathway

acts as 2° messenger

target cell

plasma membrane

binds to receptor protein

proteinhormone

ATPactivatescytoplasmicsignal

cAMP

GTP

activatesG-protein

transduction

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adrenal gland

Ex: Action of epinephrine (adrenaline)

activatesprotein kinase-A

activatesglycogen phosphorylase

activates adenylyl cyclase

epinephrine

liver cell

releasedto blood

1

25

receptorproteinin cell membrane

cytoplasm

6glycogen

activatesphosphorylase kinase

GDP

cAMP

4

activatesG protein

ATP

glucose

activates GTP

3

signal

transduction

response7

GTP

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Benefits of a 2° messenger system

Amplification!

signal

receptor proteinActivated adenylyl cyclase

amplification

amplification

amplification

amplification

GTP G protein

product

enzyme

protein kinase

cAMP

Not yetactivated

1

2

4

35

6

7

FAST response!

amplification

Cascade multiplier!

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Negative Feedback Loop

high

low

hormone 1

lowersbody condition

hormone 2

gland

specific body condition

raisesbody condition

gland

Negative FeedbackModel

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liver

pancreas

liver

Regulation of Blood Sugar

blood sugar level(90mg/100ml)

insulin

body cells takeup sugar

from blood

liver storesglycogen

reducesappetite

glucagon

pancreas

liver releasesglucose

triggershunger

high

low

FeedbackEndocrine System Control

islets of Langerhans beta islet cells

islets of Langerhansalpha islet cells

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Positive Feedback Loop

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Controlling Body Temperature

high

low

nerve signals

sweat

nerve signals

body temperature(37°C)

shiver

dilates surfaceblood vessels

constricts surfaceblood vessels

Nervous System Control Feedback

hypothalamus

hypothalamus

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Quorum Sensing in Bacteria

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Nervous & Endocrine systems linked Hypothalamus = “master nerve control center”

nervous system receives information from nerves around body

about internal conditions releasing hormones: regulates release of hormones

from pituitary

Pituitary gland = “master gland” endocrine system secretes broad range

of “tropic” hormones regulating other glands in body

hypothalamus

pituitary

posterior

anterior

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Thyroid gland

hypothalamus

anteriorpituitary

gonadotropic hormones:follicle-stimulatinghormone (FSH) & luteinizing hormone (LH)

Mammaryglandsin mammals

Musclesof uterus

Kidneytubules

posteriorpituitary

thyroid-stimulating hormone(TSH)

antidiuretic hormone(ADH)

Adrenalcortex

Boneand muscle

Testes Ovaries

Melanocytein amphibian

adrenocorticotropic

hormone (ACTH)melanocyte-stimulating hormone

(MSH)

oxytocin

prolactin (PRL)

grow

th h

orm

one

(GH

)

tropic hormones = target endocrine glands

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Homology in hormones

prolactin

mammals

milkproduction

birds

fatmetabolism

amphibians

metamorphosis& maturation

fish

salt &water

balance

growth& development

What does this tell you about these hormones?

growthhormone

same gene familygene duplication?

How could these hormones have different effects?

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