Lesson 6 - The Cell

Question 1

Homeostasis

Answer 1

Keeping internal environment constant despite a change in external environment

Question 2

Where is Homeostasis control centre? What does it do?

Answer 2

Controlled in the hypothalamus which is the bodies control centre. Receives input and controls hormones

Question 3

What do we need to keep constant in the body

Answer 3

Nutrients/ wastes
Oxygen and CO2 levels
pH
Water/electrolytes
Temperature
Blood volume and pressure

Question 4

Circadian Rhythms

Answer 4

The physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. Light and dark have biggest affect

Question 5

Homeostasis Process

Answer 5

Internal or external change
-Body attempt to correct

Successful correction
-homeostasis reestablished

failure to adjust
-death or illness

Question 6

Feedback loops

Answer 6

Negative feedback loop: Response in which the effects of a reaction slow or stop that reaction

Error occurs results in disease, over compensation or competing regulators

Positive feedback loop: occurs to increase the change or output. Response reinforces stimulus, snowball affect

Question 7

Levels of organization

Answer 7

Chemical
-molecules

cells
-basic unit of life

Tissue
-4 types

Organ

Body system

organism

Question 8

Cell subdivided into three part

Answer 8

Plasma (cell) membrane

Cytoplasm
-cytosal
-organelles

Nucleus
-chromosomes
-genes

Question 9

Cell shapes

Answer 9

cells will vary in size and contain different organelles based on function

Question 10

Nucleus

Answer 10

Cell replication and repair
Usually 1 per cell

Question 11

Ribosomes

Answer 11

-make proteins
-either free or attached
- Free, makes proteins for the cell

Question 12

Endoplasmic reticulum (ER)

Answer 12

Smooth ER
-calcium storage
- detoxification
- steroid production

Rough ER
-Ribosomes attached
- Makes organelle
- protein product for export

Question 13

Golgi complex

Answer 13

Repackages RER proteins into vesicles to leave cell

Question 14

Peroxisomes

Answer 14

Oxidative Enzymes
-Metabolism
-Detoxify various waste products

Question 15

Lysosomes

Answer 15

Sac of digestive enzymes
Used for repair and removal of foreign matter

Question 16

Proteosomes

Answer 16

Large portion complexes
-Protein digesting enzymes

With age, maybe unable to normally remove proteins

Question 17

Cytoskeleton

Answer 17

Complex protein network
-acts as “bone and muscle” of cell

Three distinct elements
-mircotubles
-microfilaments
-intermediate filaments

Question 18

Function of the three distinct elements of Cytoskeleton

Answer 18

Mircotubles
-transport secretory vesicles
-form mitotic spindle during cell division

Mircofilaments
- contractile systems
- muscle
- mechanical stiffeners

Intermediate filaments
-Help resist mechanical stress
-hair, skin

Question 19

Cilia and Flagella

Answer 19

Cilia
- directional movement of particles

Flagella
- on moving cell

Question 20

Mitochondria

Answer 20

Powerhouse of the cell and energy organelle
-site of ATP production
- Enzymes for TCA cycle and ETC

Question 21

Cellular diversity

Answer 21

Adult has roughly 100 trillion cells

• roughly 200 types of cells
• variety of shapes and sizes
  -differing lifespans
  -organize into complex tissues and organs

Question 22

Specialized function of cell is according to:

Answer 22

shape of cell and is arrangement of organelles

Question 23

Aging and cells

Answer 23

As we age:
-our cells gradually deteriorate
-number of body cells goes down
-they lose integrity of extra cellular components

Question 24

Development aspect of cells (theory)

Answer 24

Aging effecting

Free radical theory
-damage from byproducts of cellular metabolism
- radicals build up and damages essential molecules of cells

Mitochondria theory:
-decrease in production of energy weakens cells

Genetic theory:
- proposes that aging is programmed within genes
-with each replication of DNA, nucleotides are lost
-Telemeres “end caps” on chromosomes