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
AP Biology
System and Cell Communication
Agenda for 3/20
 Complete Cell Communication Booklet
Review
 My Dog is Broken - Case Study
 Cell Signaling Project Assignment
AP Biology
A. Cell Signaling
 Yeast cells

Identify their mates by cell signaling
1
Exchange of
mating factors.
Each cell type
secretes a
mating factor
that binds to
receptors on
the other cell
type.
2 Mating. Binding
of the factors to
receptors
induces changes
in the cells that
lead to their
fusion.
3
Figure 11.2
AP Biology
New a/ cell.
The nucleus of
the fused cell
includes all the
genes from the
a and  cells.
 factor
Receptor

a
Yeast cell,  factor Yeast cell,
mating type a
mating type 

a
a/
Water and Mineral Absorption –
Water Transport in Roots
Apoplastic or
symplastic
Until the
endodermis
Is reached!!
AP Biology
Translocation of Phloem SapLoading of Sugars
 Flow through the symplast or apoplast in

mesophyll cells into sieve-tube members
Active co-transport of sucrose with H+

AP Biology
Proton pump
Cell Junctions
AP Biology
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
AP Biology
Short Distance w/chemical messengers
 Neurotransmitters released by neurons
 Hormones release by endocrine glands
endocrine gland
neurotransmitter
axon
hormone
carried by blood
receptor proteins
AP Biology
receptor proteins
target cell
Lock & Key
system
Paracrine Signaling on your tongue
AP Biology
Nitric Oxide Signaling in the Penis and Heart
AP Biology
Prostaglandin Signaling by Sperm in the Uterine Cells
AP Biology
AP Biology
Endocrine System
Hormones
AP Biology
2007-2008
Regulation
 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
AP Biology
 reproduction
growth hormones
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,
AP Biology
testis and prostate development
 estrogen – female development, menstrual cycle
control (maintains lining of uterus)
 Aldosterone – controls sodium and potassium
balance and blood pressure
Steroid Hormone
AP Biology
Action of lipid (steroid) hormones
steroid hormone
target cell
S
S
cytoplasm
1
blood
S
protein
carrier
cross cell membrane
2
binds to receptor protein
becomes
transcription factor
5
S
3
mRNA read by ribosome
plasma membrane
DNA
4
mRNA
nucleus
6
protein
7
protein secreted
AP Biology
ex: secreted protein = growth factor (hair, bone, muscle, gametes)
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
insulin
 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
AP Biology
temperature and causing drowsiness
signal-transduction pathway
Action of protein hormones
1
protein
hormone
P
signal
plasma membrane
binds to receptor protein
activates
G-protein
activates enzyme
cAMP
receptor
protein
activates
cytoplasmic
signal
GTP
cytoplasm
AP Biology
target
cell
acts as 2° messenger
transduction
ATP
ATP
activates
enzyme
2
secondary
messenger
system
activates
enzyme
produces an action
3
response
Ex: Action of epinephrine (adrenaline)
adrenal gland
signal
1
epinephrine
activates
G protein
receptor
protein
in cell
membrane
activates GTP
3
activates
adenylyl cyclase
cAMP
GTP
transduction
4
GDP
2
ATP
activates
protein kinase-A
5
activates
phosphorylase kinase
cytoplasm
liver cell
AP Biology
released
to blood
activates
glycogen phosphorylase
glycogen
6
glucose
7
response
Benefits of a 2° messenger
system1
signal
Activated adenylyl cyclase
receptor protein
2
Not yet
activated
amplification
4
3
GTP
amplification
cAMP
amplification
5
G protein
protein kinase
6
amplification
Amplification!
enzyme
Cascade multiplier!
AP Biology
FAST
response!
7
amplification
product
Negative Feedback Loop
hormone 1
lowers
body condition
gland
high
specific body condition
low
raises
body condition
AP Biology
gland
hormone 2
Negative Feedback
Model
Endocrine System Control
Feedback
Regulation of Blood Sugar
islets of Langerhans
insulin
beta islet cells
liver stores
glycogen
body
cells take
up sugar
from blood
pancreas
liver
high
blood sugar level
(90mg/100ml)
low
triggers
hunger
AP Biology
liver
releases
glucose
liver
pancreas
glucagon
islets of Langerhans
alpha islet cells
reduces
appetite
AP Biology
Positive Feedback Loop
AP Biology
Nervous System Control
Feedback
Controlling Body Temperature
nerve signals
hypothalamus
dilates surface
blood vessels
sweat
high
body temperature
(37°C)
low
hypothalamus
constricts surface shiver
blood vessels
AP Biology
nerve signals
AP Biology
AP Biology
Quorum Sensing in Bacteria
AP Biology
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”


AP Biology
endocrine system
secretes broad range
of “tropic” hormones
regulating other
glands in body
hypothalamus
posterior
pituitary
anterior
tropic hormones = target endocrine glands
hypothalamus
thyroid-stimulating
hormone
(TSH)
Thyroid gland
Adrenal
cortex
posterior antidiuretic
pituitary hormone
(ADH)
anterior
pituitary
gonadotropic
hormones:
folliclestimulating
hormone (FSH)
& luteinizing
hormone (LH)
Kidney
tubules
Muscles
of uterus
Melanocyte
in amphibian
Bone
and muscle
AP Biology
Testes
Ovaries
Mammary
glands
in mammals
Homology in hormones
What does this tell you about these hormones?
How could these hormones have different effects?
same gene family
gene duplication?
prolactin
mammals
milk
production
AP Biology
birds
fat
metabolism
fish
amphibians
salt &
water
balance
metamorphosis
& maturation
growth
hormone
growth
& development
AP Biology