https:// wll798. dcqo
TRANSCRIPT
![Page 1: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/1.jpg)
Large animals- examples
https://www.youtube.com/watch?v=5m8XNwLl798
![Page 2: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/2.jpg)
Smallest animals in the world
https://www.youtube.com/watch?v=NSBaxVidcqo
![Page 3: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/3.jpg)
Do elephants and mice have the same size cells??
![Page 4: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/4.jpg)
Why aren’t cells big?
![Page 5: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/5.jpg)
Activity: Investigate Cell Size and Surface Area to Volume Ratios
![Page 6: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/6.jpg)
Minimize diffusion time
No “donut holes” No poking holes into
cell Done when 100%
color gone Disqualified if cell
breaks apart mass/time ratio
identifies winner!
Design your own cell!
![Page 7: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/7.jpg)
Print out or draw a picture of your cell (color)
Include a typed description of the cell, its function, and how it has overcome the SA:V ratio problem.
This should be on a piece of cardstock or printer paper
HW Find an example of acell that has overcome the SA:V problem.
![Page 8: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/8.jpg)
Erythrocytes, also known as red blood cells (RBCs), function to transport oxygen in the blood. The shape of erythrocytes is ideal for this function. Seen from the top, erythrocytes appear to be circular, but a side view shows that they are actually biconcaved discs. This shape increases the surface area-to-volume ratio of the cell, thus increasing the efficiency of diffusion of oxygen into and out of the cell.
The Shape of A Red Blood Cell
![Page 9: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/9.jpg)
Why aren’t cells big?
![Page 10: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/10.jpg)
![Page 11: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/11.jpg)
![Page 12: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/12.jpg)
The evolution of life required a boundary…
![Page 13: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/13.jpg)
![Page 14: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/14.jpg)
BIG IDEA 2: Cell membranes are
selectively permeable due to their structure.
Membranes and Membrane Transport
![Page 15: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/15.jpg)
Barrier Gate Keeper Communicator
Cell membranes:
![Page 16: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/16.jpg)
Lipids, proteins and carbohydrates…
The molecules of a membrane
![Page 17: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/17.jpg)
![Page 18: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/18.jpg)
phospholipids
![Page 19: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/19.jpg)
Fluid mosaic
![Page 20: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/20.jpg)
Maintaining fluidity
![Page 21: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/21.jpg)
oligosaccharides
Surface carbohydrates• Short, branched chains• Cell-cell recognition• Glycolipids• glycoproteins
![Page 22: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/22.jpg)
Membrane proteinsIntegral:
embedded in phospholipid layerfor transport, carriers, and receptorsmay or may not be transmembrane
Peripheral:found on inner or outer membrane surfaceact as point of attachment for cytoskeleton
![Page 23: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/23.jpg)
Cells must move materials through the membrane to maintain homeostasis.
How is the membrane semipermeable?
![Page 24: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/24.jpg)
Some molecules can cross without help.
![Page 25: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/25.jpg)
Transport proteins -help other molecules across cell membrane
![Page 26: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/26.jpg)
Aquaporins allow water to diffuse across the membrane
![Page 27: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/27.jpg)
Lab: Osmosis and Diffusion
![Page 28: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/28.jpg)
- moves materials against a concentration gradient. - requires Energy (ATP).
Active Transport
![Page 29: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/29.jpg)
Active Transport by membrane Proteins:
Globular proteins act as “ferries” for specific molecules shape change allows transport from one side of membrane to other
called protein pumps
![Page 30: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/30.jpg)
Many models & mechanisms--uniports, symports, antiportsprimary vs. secondary active transport
![Page 31: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/31.jpg)
The cell removes 3 sodium ions for every 2 potassium ions that enter the cell. This mechanism requires energy.
Sodium-Potassium pump
![Page 32: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/32.jpg)
Example of Transport: Absorption of Nutrients in the small intestine
Passive transport• Water, fatty acids, glyderol, some vitamins by diffusionfructose by facilitated diffusion
Active (protein pumps) transport amino acids, glucose, some vitamins against concentration gradients across intestinal cell membranes
allows intestine to absorb much higher proportion of nutrients in the intestine than would be possible with passive diffusion
worth the cost of ATP!
![Page 33: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/33.jpg)
Structure: Small IntestinesAbsorption through villi& microvilliincrease surface area
![Page 34: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/34.jpg)
Gated channelsSome channel proteins open only in presence of stimulus (signal)stimulus usually different from transported moleculeex:ion-gated channels: when neurotransmitters bind to a specific gated channels on a neuron, these channels open = allows Na+ ions to enter nerve cellex:voltage-gated channels - change in electrical charge across nerve cell membrane opens Na+& K+ channels
![Page 35: Https:// wLl798. dcqo](https://reader036.vdocuments.mx/reader036/viewer/2022081420/5697c0301a28abf838cdac03/html5/thumbnails/35.jpg)
Moving Large Molecules