BIO 1020 Unit 6
Transcript of BIO 1020 Unit 6
-
7/28/2019 BIO 1020 Unit 6
1/34
Metabolism
Unit 6
-
7/28/2019 BIO 1020 Unit 6
2/34
Definition
Metabolism
Collection of chemical reactions that takes
place in the cells
-
7/28/2019 BIO 1020 Unit 6
3/34
Metabolic activity in plants
Germinating seeds: no pigments, no photosynthesis
Embryo
How do plant seeds feed themselves?
-
7/28/2019 BIO 1020 Unit 6
4/34
-
7/28/2019 BIO 1020 Unit 6
5/34
Where is metabolism taking place?Does boiling or soaking affect it?
Boiled seed Soaked seed
3 drops of TZ
indicates (with
pink) where
metabolism is
occurring
Embryo stained red
Unstained embryo
-
7/28/2019 BIO 1020 Unit 6
6/34
Metabolism in cockroaches
What factors might account for different oxygen consumption rates?
Activity
Body size
-
7/28/2019 BIO 1020 Unit 6
7/34
Effect of temperature on oxygen consumption
There is a positive relationship between ambient temperature and metabolic ratefor roaches as measured by changing oxygen consumption rates
Metabolic activity is a series of chemical reactions and these reactions respond to
temperature
-
7/28/2019 BIO 1020 Unit 6
8/34
Weight-specific oxygen consumption rates
Weight-specific O2 consumption rate =
O2 consumption rate
Weight of roach
-
7/28/2019 BIO 1020 Unit 6
9/34
How do gases involved in metabolism enter andleave cells?
Gas exchange systems in terrestrial animals
Diffusion of oxygen from the medium into the blood.
Transport of oxygen to the tissues and cells of the body.
Diffusion of oxygen from the blood into cells.
Carbon dioxide follows a reverse path
DIFFUSION
-
7/28/2019 BIO 1020 Unit 6
10/34
Insect respiratory system
-
7/28/2019 BIO 1020 Unit 6
11/34
Insect respiratory system Tracheal system
Air enters through spiracles and travels within the trachea to reach the
bodys cells for gasexchangeoccurs via diffusion
The tracheae branches into smaller tubes, called tracheoles
-
7/28/2019 BIO 1020 Unit 6
12/34
Epiglottis
Larynx
Esophagus
Trachea
Bronchus
(2)
Diaphragm
Bronchiole
Arteriole
Venule
Alveoli
*Pathway of air
-
7/28/2019 BIO 1020 Unit 6
13/34
Human respiratory system
Lungs are sub-divided into tiny air sacs (alveoli) Why?
to increase surface area for gas exchange
Gas exchange occur in thealveoli
Oxygen enter the capillaries by diffusion
Carbon dioxide leaves the blood and enter the alveolus by diffusion
-
7/28/2019 BIO 1020 Unit 6
14/34
How is the air taken into the lungs?
-Contraction of diaphragm increases volume within chest cavity
-Pressure is reduced inside chest cavity compared to atmospheric pressureoutside the body
-Air is pushed into the lungs by the greater pressure outside the body
-Gas laws: same volume of gas in a larger space will have a lower pressure
-
7/28/2019 BIO 1020 Unit 6
15/34
What is the function of the epiglottis?
-The epiglottis is usually upright at rest allowing air to pass into the larynx and
lungs.
-The epiglottis folds backward to cover the entrance of the larynx so food and
liquid do not enter the trachea and lungs.
-
7/28/2019 BIO 1020 Unit 6
16/34
Thermal strategies for animal metabolism
Sets of adaptations and responses to
environmental temperature
Ectotherms- control body temperature through
external means , such as the sun, or flowing
air/water.Examples of temperature control include:Snakes and lizards sunning themselves on rocks.
Fish changing depths in the water column to find a suitable
temperature.
Desert animals burrowing beneath the sand during the day.
Insects that warm their flight muscles by vibrating them in
place.
http://en.wikipedia.org/wiki/Snakehttp://en.wikipedia.org/wiki/Lizardhttp://en.wikipedia.org/wiki/Fishhttp://en.wikipedia.org/wiki/Deserthttp://en.wikipedia.org/wiki/Insecthttp://en.wikipedia.org/wiki/Insecthttp://en.wikipedia.org/wiki/Deserthttp://en.wikipedia.org/wiki/Fishhttp://en.wikipedia.org/wiki/Lizardhttp://en.wikipedia.org/wiki/Snake -
7/28/2019 BIO 1020 Unit 6
17/34
Thermal strategies for animal metabolism
Sets of adaptations and responses to
environmental temperature
Endotherms- control their body temperatures through
internal means such as muscle shivering, fat burning,
sweating, panting
-
7/28/2019 BIO 1020 Unit 6
18/34
Ectotherms
-
7/28/2019 BIO 1020 Unit 6
19/34
ECTOTHERMS
O2 CONSUMPTION
VARIES WITH
TEMPERATURE
-
7/28/2019 BIO 1020 Unit 6
20/34
-
7/28/2019 BIO 1020 Unit 6
21/34
ENDOTHERMSCan maintain constant O2 consumption across a
broad range of temperatures.
-
7/28/2019 BIO 1020 Unit 6
22/34
Metabolic rate and body size
Some general patterns:
Endotherms are typically larger than ectotherms
At any size, endotherms consume more oxygen thanectotherms.
In other words, the endotherm strategy is energetically
expensive.
-
7/28/2019 BIO 1020 Unit 6
23/34
Pros and Cons to each strategy
Ectotherms: inexpensive strategy, dont have to consume asmuch food as endotherms do less searching, less risky
However, ectotherms are prisoners of their environments.
Cannot exploit the environment like an endotherm.
Endotherms: expensive strategy, have to consume lots of
food searching costs
Endotherms are able to exploit the environment. They can
live in a wide range of habitats.
-
7/28/2019 BIO 1020 Unit 6
24/34
Metabolic rate and body size in Endotherms
Smaller ENDOTHERMS have
HIGHER metabolic rates than largerendotherms:
Need more ENERGY to maintain
body temperature due to higher
SA:Volume ratios
-
7/28/2019 BIO 1020 Unit 6
25/34
Metabolic rate and body size
Endotherms have a enormous
weight-specific oxygen
consumption rate
Cat consumes oxygen at a rate
of 0.44 ml/g/h
Human consumes 0.21 ml/g/h
A 20 g shrew would consume 3.5ml/g/h
It is very expensive to be an
endotherm
-
7/28/2019 BIO 1020 Unit 6
26/34
1. The graph below illustrates the effect of increased temperature on
metabolic rate in an aquatic ectotherm, Daphnia magna (water "flea").
What is the relationship between metabolic rate and a 10C increase in
temperature?
Each 10C increase in temperature results in a doubling of the
metabolic rate.
-
7/28/2019 BIO 1020 Unit 6
27/34
2. In the lungs, oxygen and carbon dioxide move in and out of the alveoli and
capillary network by which process?
Diffusion
3. What specific effect does high temperature have, in order to cause the sharp
decline in oxygen consumption above 35oC?
Denaturation of enzymes
-
7/28/2019 BIO 1020 Unit 6
28/34
4. If the environmental temperature (-1oC) is below body temperature, what
does your body do to maintain a relatively constant temperature?
Muscle Shivering
-
7/28/2019 BIO 1020 Unit 6
29/34
Sample test items
1. Which of the following animals has the highest WSOCR?
AnimalPuppy
Mouse
kitten
Weight800 g
30
500
O2 consumption5.0 ml/min
1.0
5.0
0.006
0.03
0.01
WSOCR
-
7/28/2019 BIO 1020 Unit 6
30/34
Which of the following is a benefit to the endothermic
strategy?
A) Allows an organism to have a smaller body size
B) Allows an organism to maximize activity over a wider
range of environmental temperatures
C) Allows an organism to take advantage of unpredictableresource availability
D) Allows an organism to have lower energy requirements
-
7/28/2019 BIO 1020 Unit 6
31/34
-
7/28/2019 BIO 1020 Unit 6
32/34
Metabolism in cockroaches
Changes in gas volume in response to normal metabolic activity
Oxygen consumption is determine by measuring the distance the blue dye moves down theglass tube
KOH
KOH
Distance bubble moved Volume Rate
distance X 0.0962 volume/time
mm ml ml/min
Carbon
dioxide
-
7/28/2019 BIO 1020 Unit 6
33/34
Effect of temperature on oxygen consumption
There is a positive relationship between ambient temperature and metabolic ratefor ectotherms as measured by changing oxygen consumption rates
Metabolic activity is a series of chemical reactions and these reactions respond to
temperature
KOH
KOH
-
7/28/2019 BIO 1020 Unit 6
34/34
endotherms
ectotherms