Download Practice Worksheet Lecture 2 : Nutrition, Digestion, Absorption

University of Arizona
182 INTRODUCTORY BIOLOGY
Spring 2010
Dr. Regis Ferriere
Practice Worksheet
Lecture 2 : Nutrition, Digestion, Absorption, Excretion
Corresponding sections in Biological Science (Freeman, 3rd or 2nd ed.)
Chapter 42 : 42.4
Chapter 43 : 43.1, 43.3, 43.4
Review important information
1. What does our body need from food ?
2. How many amino acids are there and how many do we need from the food we eat ?
3. What are vitamins and how do they function ?
4. What is digestion ?
5. Where does most absorption occur, and what structures contribute to absorption efficieny ?
6. How do animals avoid digesting themselves ?
7. Where and how does digestion start ?
8. How does the stomach break down ingested food ?
9. How and where does the digestion of protein start ?
10. What happens in the duodenum ?
11. What are the key roles of the liver in digestion ?
12. What are the key roles of the pancreas in digestion ?
13. How is glucose homeostasis achieved ?
14. What is bioaccumulation ?
15. Define osmosis and osmolarity.
16. What is the function of excretory organs ?
17. What are the end products of metabolism of carbohydrates ? fats ? proteins ?
18. What is the remarkable adaptation that has evolved in birds and mammals’ kidney ? Under
what main selection pressure ?
19. How does water reabsorption happen in the mammalian kidney ?
20. What are the key hormones involved in the regulation of kidney function ?
Test your knowledge
Q1. Food provides humans with the eight _____ and thirteen _____ that they need. ____ like
____ are needed in small or trace amounts. ____ is a ____ that is required for bone growth.
A. Macronutrient
B. Calcium
C. Vitamins
D. Micronutrients
E. Essential amino acids
F. Iron
Q2. Food is broken down by ____ which are secreted in inactive forms called ____. For
example, ____ results from the activation of ____ (secreted by ____) by low pH in the stomach.
Low pH is caused by the release of HCl by ____. Pepsin initiates the digestion of ____ in the
stomach. The digestion of lipids start in the first section of the ____ called ____.
A. Chief cells
B. Proteins
C. Small intestine
D. Digestive enzymes
E. Zymogen
F. Pesinogen
G. Duodenum
H. Pepsin
I. Parietal cells
Q3. The main excretory organ in mammals is the ____. Excretory organs control the
composition and concentration of extracellular fluid by three mechanisms: ______. The
composition is controlled so that toxic wastes like ____ are eliminated. The concentration is
controlled so that ____ is minimized.
A. Digestion, absorption, secretion
B. Nutrition, filtration, secretion
C. Filtration, secretion, reabsorption
D. HCl
E. Liver
F. Ammonia
G. Kidney
H. Water loss
I. Pancreas
J. Heat gain
K. CO2
L. Uric acid production
Q4. Blood is filtered in the ____, which is part of the functional unit of the kidney called ____.
After filtration pre-urine moves to the ____ in the _____ that form the ____. The ____ is _____
to water and _____ to solutes, whereas the _____ is _____ to water and _____ to Na+ and Cl-.
A. impermeable
B. permeable
C. descending limb
D. loop of Henle
E. glomerulus
F. ascending limb
G. tubules
H. nephron
I. medulla.
Q5. When blood pressure falls or osmolarity varies, ____ are released. Lower blood pressure
triggers production of ____ which causes release of ____, resulting in greater ____ and ____
sensation. Change is osmolarity triggers secretion of ____, causing ____ to fuse with _____ of
cells of ____. Greater ____ also results.
A. water reabsorption
B. aquaporins
C. hormones
D. membrane
E. renin and angiotensin
F. ADH (antidiuretic hormone)
G. collecting ducts
H. aldosterone
I. thirst