1. Why are organic macromolecules so important to consume in the diet?

2. Why are organic macromolecules so important to consume in the diet
Why are organic macromolecules so important to consume in the diet? The body utilizes these macromolecules to yield energy.

3. Energy-Yielding Molecules
Carbohydrates
Fats
Proteins
Describe the fate of each of these molecules following digestion.

4. Energy-Yielding Molecules
Carbohydrates
Fats
Proteins
Describe the fate of each of these molecules following digestion.
Sugars are utilized in CR first, then excess gets converted to glycogen or fat. Fats are usually stored as a longer-term energy reserve. Proteins (amino acids) are utilized as necessary, but cannot get stored.

5. Nitrogenous Waste = Metabolic Waste

6. Organisms must EXCRETE metabolic waste.
Metabolic Wastes
Nitrogenous
Carbon dioxide
Water
Salts (phosphates, sulfates, etc.)
Organisms must EXCRETE metabolic waste.

7. Considering evolutionary history, organismal systems were simple and became more complex. The need to excrete metabolic wastes (nitrogenous) efficiently evolved as organisms transitioned from water to land.

8. Evolution of Metabolic Wastes
Important Factors
Need to conserve water
Solubility in water
Toxicity
Energy Cost

9. Body Fluid Regulation
The Excretory system is involved in regulating body fluid concentrations.
How? By retaining or eliminating certain ions and water
OSMOSIS: Water moves from on area of higher concentration (less solute) to an area of lower concentration (higher solute).

10. Forms of Nitrogenous Waste

11. Soluble Ammonia Urea Uric Acid Very soluble Very toxic
Found in organisms that
do not need to conserve water
Urea
Soluble
Toxic
Found in organisms that conserve
some water
Uric Acid
Not Toxic
Not Soluble
Found in organisms that
must conserve all water
some waste

12. Considering the type of environment that the organism of interest lives in, you can predict the nitrogenous waste form that is excreted.

13. Let’s consider the excretion of nitrogenous wastes in the Paramecium Which nitrogenous waste form is most likely excreted by the Paramecium? How are wastes excreted in the Paramecium?

14. Let’s consider the excretion of nitrogenous wastes in the Paramecium Which nitrogenous waste form is most likely excreted by the Paramecium? AMMONIA How are wastes excreted in the Paramecium? SIMPLE DIFFUSION

15. Which Nitrogenous Waste form is excreted by the Cnidarians
Which Nitrogenous Waste form is excreted by the Cnidarians? How is the life process of excretion enabled in the Cnidarians?

16. Which Nitrogenous Waste form is excreted by the Cnidarians
Which Nitrogenous Waste form is excreted by the Cnidarians? AMMONIA How is the life process of excretion enabled in the Cnidarians?

17. Phylum: Cnidaria Excretion excrete metabolic wastes by diffusion
between cell layers
out through mouth
excrete salt into gastrovascular cavity
regulate water balance

18. Which Nitrogenous Waste form is excreted by the Platyhelminthes
Which Nitrogenous Waste form is excreted by the Platyhelminthes? How is the life process of excretion enabled in the Platyhelminthes?

19. Which Nitrogenous Waste form is excreted by the Platyhelminthes
Which Nitrogenous Waste form is excreted by the Platyhelminthes? Aquatic- Ammonia, Terrestrial- Urea How is the life process of excretion enabled in the Platyhelminthes?

20. The simplest tubular excretory system is the flame-cell system of flatworms. These animals have neither circulatory systems nor coeloms, and so the flame-cell system must regulate the contents of the interstitial fluid directly.

21. Phylum: Platyhelminthes Class: Turbellaria
simple excretory system- protonephridia
consists of flame cells (specialized ciliated cells)
move fluid through branched ducts to outside via excretory pores
maintains osmotic balance

23. Which Nitrogenous Waste form is excreted by the Mollusks
Which Nitrogenous Waste form is excreted by the Mollusks? How is the life process of excretion enabled in the Mollusks?

24. Which Nitrogenous Waste form is excreted by the Mollusks
Which Nitrogenous Waste form is excreted by the Mollusks? Aquatic- Ammonia, Terrestrial- Urea How is the life process of excretion enabled in the Mollusks?

25. Visceral mass
Mantle
Foot
Coelom
Intestine
Gonads
cavity
Anus
Gill
Nerve
cords
Esophagus
Stomach
Shell
Radula
Mouth
Nephridium. Excretory organs
called nephridia remove metabolic
wastes from the hemolymph.
Heart. Most molluscs have an open circulatory
system. The dorsally located heart pumps
circulatory fluid called hemolymph through arteries
into sinuses (body spaces). The organs of the
mollusc are thus continually bathed in hemolymph.
The long digestive tract is
coiled in the visceral mass.
Radula. The mouth
region in many
mollusc species
contains a rasp-like
feeding organ
called a radula. This
belt of backward-
curved teeth slides
back and forth,
scraping and
scooping like a
backhoe.
The nervous
system consists
of a nerve ring
around the
esophagus, from
which nerve
cords extend.
Figure 33.16

26. Annelids have similar excretory structures as the Mollusks

27. Anatomy of the earthworm -Contain two nephridia in each segment -

28. Earthworm Nephridia
Nephridia: Tubule with ciliated opening an an excretory pore.
Fluid from the coelom is propelled through the tubule by beating cilia, nutrient substances are reabsorbed and carried away by a network of capillaries surrounding the tubule.
Urine: Contains metabolic wastes, salts, water

29. How does the habitat of insects (e. g
How does the habitat of insects (e.g. grasshoppers) differ to that of the other organisms discussed prior?

30. How does the habitat of insects (e. g
How does the habitat of insects (e.g. grasshoppers) differ to that of the other organisms discussed prior? Insects tend to live in drier habitats and require more water to be conserved.

31. Which Nitrogenous Waste form is excreted by the Arthropods
Which Nitrogenous Waste form is excreted by the Arthropods? How is the life process of excretion enabled in the Arthropods?

32. Which Nitrogenous Waste form is excreted by the Arthropods
Which Nitrogenous Waste form is excreted by the Arthropods? Aquatic- Ammonia, Terrestrial- Uric Acid How is the life process of excretion enabled in the Arthropods?

33. Grasshopper Anatomy

34. Malpighian Tubules
These specialized tubules are attached to the gut of arthropods.
Uric acid flows from the surrounding hemolymph into these tubules, and water follows a salt gradient established by active transport of K+.
Water and other useful substances are reabsorbed at the rectum. Excrete a dry, semisolid mass of uric acid.

35. Excretion in Insects and Arachnids

36. Organisms utilize some form of excretory structure to excrete nitrogenous waste. IMPORTANT The form of nitrogenous waste is completely dependent on the environment and the need to conserve water.

37. Human Excretory System (HES)

38. Urea is made in the mitochondrion of liver cells
Urea is made in the mitochondrion of liver cells. Urea then circulates in the bloodstream until it reaches the structures of the HES.

40. Identify the structures of the Human Excretory System that enable the function of the removal of nitrogenous waste.

42. Filtration of blood begins in the kidneys
Filtration of blood begins in the kidneys. Why does blood need to be filtered?

44. How is the kidney structured to enable the function of filtration?

46. The functional unit of the kidney is the Nephron.

48. Whole blood traveling from renal artery enters into the Glomerulus (small capillary structures arranged into a cup-like structure). Which molecules are going to easily enter into Bowman’s capsule?

50. WHAT IS THE PROBLEM WITH CAPSULAR URINE?
Amino acids
Nutrients
Electrolytes
Water
Gases
Nitrogenous waste
WHAT IS THE PROBLEM WITH CAPSULAR URINE?

51. WHAT IS THE PROBLEM WITH CAPSULAR URINE?
Amino acids
Nutrients
Electrolytes
Water
Gases
Nitrogenous waste
WHAT IS THE PROBLEM WITH CAPSULAR URINE?
There is good stuff that is potentially going to be excreted and released in urine.

53. Proximal convoluted tubule is the site of selective reabsorption.

54. Tubular Reabsorption
Substances that are biologically important move from the proximal convoluted tubule into the surrounding peritubular capillaries.
Sodium and chloride ions are actively pumped from PCT to the PTC, enabling water to follow.
Glucose and amino acids are selectively reabsorbed by carrier proteins- Active transport.

55. Urine formation and Concentration

57. There are three hormones critical in maintaining the water content of the blood.

58. Hormones
Antidiuretic Hormone (ADH)- Makes the collecting duct more permeable. It is secreted by the posterior pituitary gland in response to an increase in the osmotic pressure of the blood.
Aldosterone- Acts on the kidneys to retain sodium ions, therefore water is reabsorbed and blood pressure rises as a result of increased blood volume.
Renin- Kidneys release renin in the event of low blood pressure. The presence of renin causes the release of angiotensin II, which causes the adrenal cortex to release aldosterone.