AP Biology

December 5, 2011 BellRinger

Final presentations

Objective Differentiate between various mechanisms

of excretion of nitrogenous wastes

Homework Chp 44 notes completed Chp 42 notes by Thursday

AP Biology

Kidney Structure& Function

Collecting ductLoop of Henle

Aminoacids

Glucose

H2O

H2O

H2O

H2O

H2O

H2O

Na+ Cl-

Mg++ Ca++Na+ Cl-

Removing IntracellularWaste

AP Biology

intracellular waste

Animal systems evolved to support multicellular life

O2

CHO

CHO

aa

aa

CH

CO2

NH3aa

O2

CH

O2

aa

CO2

CO2

CO2

CO2

CO2

CO2 CO2

CO2

CO2

CO2

NH3

NH3 NH3

NH3

NH3

NH3

NH3NH3

O2

aa

CH

aa

CHO

O2

Diffusion too slow!

single cell

but whatif the

cells areclustered?

for nutrients in & waste out

extracellular waste

AP Biology

Overcoming limitations of diffusion Evolution of exchange systems for

distributing nutrients circulatory system

removing wastes excretory system

systems to support multicellular organisms

systems to support multicellular organisms

aa

CO2

CO2

CO2

CO2

CO2

CO2 CO2

CO2

CO2

CO2

NH3

NH3 NH3

NH3

NH3

NH3

NH3NH3

O2

aa

CH

aa

CHO

O2

AP Biology

Osmoregulation

Why do all land animals have to conserve water?

always lose water (breathing & waste) may lose life while searching for water

Water balance vs. Habitat freshwater

hypotonic to body fluids water flow into cells & salt loss

saltwater hypertonic to body fluids water loss from cells

land dry environment need to conserve water may also need to conserve salt

hypotonic

hypertonic

AP Biology

Intracellular Waste What waste products

are made inside of cells? what do we digest our food into…

carbohydrates = CHO lipids = CHO proteins = CHON nucleic acids = CHOPN

CO2 + H2O

NH2=ammonia

CO2 +H2O CO2 +H2O

CO2 +H2O + N

CO2 +H2O + P + N

|

| ||H

HN C–OH

O

R

H–C–

Animalspoison themselves

from the insideby digesting

proteins!

lots!verylittle

cellular digestion…cellular waste

AP Biology

Nitrogenous waste disposal Ammonia (NH3)

very toxic carcinogenic

very soluble easily crosses membranes

must dilute it & get rid of it… fast!

How you get rid of nitrogenous wastes depends on who you are (evolutionary relationship) where you live (habitat)

aquatic terrestrial terrestrial egg layer

AP Biology

Nitrogen waste Aquatic organisms

can afford to lose water ammonia

most toxic

Terrestrial need to conserve

water urea

less toxic

Terrestrial egglayers

need to conserve water need to protect

embryo in egg uric acid

least toxic

AP Biology

Freshwater animals Hypotonic environment

water diffuses into cells

Manage water & waste together remove surplus water & waste

use surplus water to dilute ammonia& excrete it also diffuse ammonia continuously through gills

overcome loss of salts reabsorb in kidneys or active transport across gills

AP Biology

Land animals Nitrogen waste disposal on land

need to conserve water must process ammonia so less toxic

urea = larger molecule = less soluble = less toxic 2NH2 + CO2 = urea produced in liver

kidney filter solutes out of blood reabsorb H2O (+ any useful solutes) excrete waste

urine = urea, salts, excess sugar & H2O urine is very concentrated concentrated NH3 would be too toxic

OC

HNH

HNH

Ureacosts energyto synthesize,

but it’s worth it!

mammals

AP Biology

Egg-laying land animals

itty bittyliving space!

Nitrogen waste disposal in egg no place to get rid of waste in egg need even less soluble molecule

uric acid = BIGGER = less soluble = less toxic birds, reptiles, insects

AP Biology

N

N N

N

O

HO

O

H

HH

Uric acid Polymerized urea

large molecule precipitates out of solution

doesn’t harm embryo in eggwhite dust in egg

adults still excrete N waste as white pasteno liquid wasteuric acid = white bird “poop”!

AP Biology

Too much Uric Acid Gouty arthritis

Inflammation of joints is caused by a deposition of uric acid crystals from the blood

Can usually be controlled with a low protein diet

AP Biology

Learning Check Given two animals the same size, which

would produce more nitrogenous wastes- an herbivore, or a carnivore? Explain

Vertebrates that produce shelled eggs excrete ______

Mammals produce __________ What adaptive advantage do these types

of nitrogenous wastes provide?

AP Biology

Non-Mammalian Excretory systems In 3 larger groups, you will be responsible for

becoming the community experts on a non-mammalian excretory system Protonephridia Metanephridia Malpighian tubes

As an excretory expert, be able to answer the following questions about your system:

1. Example organisms with this system2. Osmoregulation, excretion, or both?3. How does the system work?4. What is the relationship between the location

and how it works?5. How does the structure support its function?

AP Biology

December 6, 2011 BellRinger Quiz

What is the functional unit of the kidney? (which structure does all of the work?-Hint-there’s over 1 million of them in each kidney)

Briefly list the processes that take place in this structure

Objective List and describe the structures and function of

the mammalian excretory system

Homework Chp 42 notes by Thursday

AP Biology

In your NUMBERED Groups, discuss the information you found regarding your system

Protonephridia Metanephridia Malpighian tubes

You are the expert in your group, so make sure your team has the info they need

http://www.biology.ualberta.ca/courses.hp/zool250/animations/Excretion.swf

Non-Mammalian Excretory systems

AP Biology

Mammalian Kidney

kidney

bladder

ureter

urethra

renal vein& artery

nephron

microvilli onepithelial

cells

adrenal glandinferior

vena cavaaorta

AP Biology

What is Urinalysis? Urinalysis – or the

analysis of urine – is one of the oldest laboratory procedures in the practice of medicine.

It is a good test for assessing the overall health of a patient.

Courtesy of the National Library of Medicine

AP Biology

What is Urinalysis? It provides information about:

The state of the kidney and urinary tract.

Metabolic or systemic (non-kidney) disorders.

Urinalysis can reveal diseases that have gone unnoticed because they do not produce striking signs or symptoms. Examples include diabetes mellitus,

various forms of kidney failure, and chronic urinary tract infections.

More on a Urinalysis

AP Biology

Nephron Functional units of kidney

1 million nephronsper kidney

Function filter out urea & other

solutes (salt, sugar…) blood plasma filtered

into nephron high pressure flow

selective reabsorption ofvaluable solutes & H2O back into bloodstream greater flexibility & control

“counter current exchange system”

whyselective reabsorption

& not selectivefiltration?

AP Biology

Draw a nephron, fill in info on the following slides

AP Biology

Mammalian kidney

Proximaltubule

Distal tubule

Glomerulus

Collecting ductLoop of Henle

Aminoacids

Glucose

H2O

H2O

H2O

H2O

H2O

H2O

Na+ Cl-

Mg++ Ca++

Interaction of circulatory & excretory systems

Circulatory system glomerulus =

ball of capillaries Excretory system

nephron Bowman’s capsule loop of Henle

proximal tubule descending limb ascending limb distal tubule

collecting duct

How candifferent sectionsallow the diffusion

of different molecules?

Bowman’s capsule

Na+ Cl-

AP Biology

Mammalian System Filter solutes out of blood & reabsorb

H2O + desirable solutes Key functions

filtration fluids (water & solutes) filtered out

of blood Blood Urine

reabsorption selectively reabsorb (diffusion) needed

water + solutes back to blood Urine Blood

secretion pump out any other unwanted solutes to

urine Blood Urine

excretion expel concentrated urine (N waste +

solutes + toxins) from body Video

blood filtrate

concentratedurine

AP Biology

Nephron: Filtration At glomerulus

filtered out of blood H2O

glucose salts / ions (Na+ / Cl–) urea

not filtered out cells proteins

high blood pressure in kidneysforce to push (filter) H2O & solutes out of blood vessel

high blood pressure in kidneysforce to push (filter) H2O & solutes out of blood vessel

BIG problems when you start out with high blood pressure in systemhypertension = kidney damage

BIG problems when you start out with high blood pressure in systemhypertension = kidney damage

H2O

&solutes

cells &large

molecules

AP Biology

Nephron: Re-absorption Proximal tubule

reabsorbed back into blood NaCl

active transport of Na+

Cl– follows by diffusion

H2O

glucose HCO3

-

bicarbonate buffer for

blood pH

AP Biology

Nephron: Re-absorptionstructure fits

function! Loop of Henle descending limb reabsorbed

H2O structure

many aquaporins in cell membranes

high permeability to H2O

no Na+ or Cl– channels impermeable

to salt

AP Biology

Nephron: Re-absorptionstructure fits

function! Loop of Henle ascending limb reabsorbed

Na+&Cl–

structure many Na+ / Cl– channels

in cell membranes high permeability

to Na+&Cl–

no aquaporins impermeable to H2O

AP Biology

Nephron: Re-absorption Distal tubule

reabsorbed salts H2O

bicarbonate HCO3

-

regulate blood pH

AP Biology

Nephron: Reabsorption &Excretion Collecting duct

reabsorbed H2O = through

aquaporins excretion

concentrated urine

to bladder impermeable

lining = no channels in cell membranes

AP Biology

Osmotic control in nephron How is all this re-absorption achieved?

tight osmotic control to reduce the energy costof excretion

use diffusioninstead of active transportwherever possible

the value of acounter current exchange system

AP Biology

Summary Not filtered out of blood

Cells,proteins remain in blood (too big)

Reabsorbed back to blood: active transport Na+,amino acids,glucose

Reabsorbed back to blood: diffusion H2O, Cl–

Excreted out of body urea excess H2O,excess solutes (glucose, salts) toxins, drugs, “unknowns”

whyselective reabsorption

& not selectivefiltration?

AP Biology

When the Kidneys Fail Kidney function

Real Story- Hemodialysis

AP Biology

Any Questions?