1. What does it mean to be living?
maintain boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth

2. 1) Maintain boundaries
The "inside" must be distinct from the "outside"
Cellular level: membranes
holds in the organelles
lets in necessary substances
prevents entry to damaging or unnecessary substances
Organismal level: skin (integumentary system)
holds in our organs and lines all of our organs
protects internal organs from drying out, bacteria, damaging effects of heat/sunlight/chemicals

3. 2) Movement locomotion movement of substances
blood: cardiovascular
food: digestive
urine: urinary
Cellular level: movement of substances such as blood/foodstuffs/urine through internal organs
Organismal level: movement promoted by muscular system
works hand-in-hand with skeletal system

4. 3) Responsiveness
the ability to sense changes in the environment and then react to them
Cellular level: nerve cells are very responsive and can communicate and send off impulsive
all body cells are responsive to some extent
Organismal level: your own reflexes!
burning your hand on a stove elicits a response from the muscular system
buildup of CO2 in the blood elicits a response from the respiratory system

5. 4) Digestion
the process of breaking down ingested food into simple molecules that can be absorbed
Cellular level:
intracellular digestion: occurs within the cell
single-celled organisms like amoeba and protozoans
extracellular digestion: occurs outside the cell through the secretion of enzymes
worms, insects, crustaceans
Organismal level: digestive system
mouth, stomach, small/large intestine

6. 5) Metabolism
a broad term that refers to all chemical reactions that occur within body cells
production of energy
making body structures
Cellular level: breaking down complex substances into smaller building blocks and using oxygen/nutrients to make ATP
Organismal level:
Digestive and respiratory system make nutrients and oxygen available to blood
Cardiovascular system distribute substances throughout the body
Endocrine system regulates metabolism

7. 6) Excretion Excretion: the process of removing wastes from the body
Cellular level: exocytosis
removes cellular wastes
Organ level:
Digestive system rids body of food residues through feces (poop)
Urinary system disposes of nitrogen-containing metabolic wastes in urine (pee)

8. 7) Reproduction production of offspring
Cellular level: original cell divides to produce two identical daughter cells
Sound familiar? Mitosis!
Organismal level:
Reproductive system components (egg and sperm) unite to eventually form a baby
Endocrine system regulates the hormones associated with the reproductive system

9. 8) Growth
increase in size, usually accomplished by an increase in the number of cells
For this life function, only the cellular level exists

10. What do you need to survive?
Kumbaya definition

11. What do you need to survive?
Textbook definition
Nutrients
chemicals for energy and cell building
includes carbohydrates, proteins, lipids, vitamins, minerals
Oxygen
required for chemical reactions
cellular respiration, anybody?

12. What do you need to survive?
Water
60-80% of body weight
provides for metabolic reactions
Stable body temperature
Appropriate atmospheric pressure

13. How does the body regulate what we need?
Homeostasis: the body’s ability to maintain relatively stable internal conditions even though the outside world is constantly changing
a dynamic state state of equilibrium
connect “dynamic” to lit term (dynamic character is one that changes over the course of the story)

14. Homeostasis regulates temperature, water balance, pH balance, ion/mineral balance, organic compound balance, gaseous content balance

15. How are these conditions controlled?
Feedback mechanisms
a control mechanism which monitors a specific quantity, then is able to make a change so that the quantity is changed

16. Negative feedback
The net effect of the response to the stimulus is to shut off the original stimulus or reduce its intensity
Our bodies work the same way
our “thermostat” is the our hypothalamus
Other negative feedback mechanisms regulate heart rate, blood pressure, breathing rate, and blood levels of glucose/oxygen/carbon dioxide/minerals

17. Positive Feedback
increases the original disturbance and pushes the variable farther from its original value
blood clotting and birth of a baby
contractions keep getting more and more intense and hormones kept at abnormal levels until the baby is born