Year 11 Bio homework problems?
Topic: Homework forms of energy
May 25, 2019 / By Guinevere Question:
Having some trouble with bio homework, any input would be appreciated.
Heres the question:
Describe the current model of membrane structure and explain how it accounts for the movement of some substances into and out of cells.
Best Answers: Year 11 Bio homework problems?
Diane | 3 days ago
The membrane structure refers to the cell membrane.
The cell membrane is semi-permeable, this means that it allows certain substances in and out:
Three interesting points about a cell membrane can be found below:
1. Passive diffusion and osmosis: Some substances (small molecules, ions) such as carbon dioxide (CO2), oxygen (O2), and water, can move across the plasma membrane by diffusion, which is a passive transport process. Because the membrane acts as a barrier for certain molecules and ions, they can occur in different concentrations on the two sides of the membrane. Such a concentration gradient across a semipermeable membrane sets up an osmotic flow for the water.
2. Transmembrane protein channels and transporters: Nutrients, such as sugars or amino acids, must enter the cell, and certain products of metabolism must leave the cell. Such molecules are pumped across the membrane by transmembrane transporters or diffuse through protein channels. These proteins, also called permeases, are usually quite specific, recognizing and transporting only a limited food group of chemical substances, often even only a single substance.
3. Endocytosis: Endocytosis is the process in which cells absorb molecules by engulfing them. The plasma membrane creates a small deformation inward, called an invagination, in which the substance to be transported is captured. The deformation then pinches off from the membrane on the inside of the cell, creating a vesicle containing the captured substance. Endocytosis is a pathway for internalizing solid particles (cell eating or phagocytosis), small molecules and ions (cell drinking or pinocytosis), and macromolecules. Endocytosis requires energy and is thus a form of active transport.
👍 174 | 👎 3
Did you like the answer? Year 11 Bio homework problems?
Share with your friends
We found more questions related to the topic: Homework forms of energy
Originally Answered: 13 year old with growing family problems?
Tell your mum how u feel and if she says she doesn't care then.. talk with another adult that you like and trust and ask them to talk with your mother about how you feel. She may listen then. Email me if this doesn't work or anything. My email address is [email protected]
The cellular membrane is made of phospholipids, proteins, cholesterol, and more. So there are several ways stuff can get in and out. Polar molecules either diffuse through the membrane slowly or go through protein channels or other proteins such as aquaporins which allow water to travel through the membrane quickly. Nonpolar items such as hormones (not all hormones) can enter a cell through the membrane quickly by diffusion through the layer of phospholipids. Big items such as starch need transport proteins and such. Imagine there are 1 million people in a room and someone yells fire. All the fat people will have trouble squishing through the doors together but skinny people can get by easier. On top of that, if there are more doors, more people can exit. That is why there are folds in the membrane to allow for more surface area.
👍 70 | 👎 -6
I are living in Florida and we go within the equal order. I believe every college now does algebra then geometry then algebra 2. You will have to at least are attempting the entire problems and when you can't get a few of them, there's nothing you are able to do. I suppose you're going to just have got to hope that your instructor is not going to care. Summer time homework is absolutely now not perpetually a completion grade. My teachers have spent a long time grading summer season homework and they grade it beautiful harshly. I guess it relies on the institution. You should ask individuals who've taken that class earlier than.
👍 68 | 👎 -15
It is made out of a phospholipid bilayer which is able to repel water. It has protiens that dot it that allow substance that it needs in and keeps bad things out. This is called selective permeability.
👍 66 | 👎 -24
Originally Answered: What problems are caused if a female dog tried to breed before they are one year old?
I'd have the litter aborted and spay her. A female that young can have whelping difficulties, especially since you don't know how large the sire was. She can reject or even kill her own litter due to immaturity. ANY pregnant female can die whelping. No dog should breed until they are at least TWO years old so they can be properly tested and OFA'd for genetic problems. To be a RESPONSIBLE breeder, you should do all this BEFORE breeding, and since this one wasn't planned, I'd end it.
1. Contact a breed club for your breed. Ask for a mentor.
2. STUDY the breed standard. Learn about dog anatomy and ask your mentor to
clarify anything you don't understand.
3. Learn what genetic faults and diseases run in your breed and test for any
that can be tested for.
4. Show your dog in conformation events to see if it is of the proper
quality for breeding. Winning doesn't always mean a dog is breeding quality,
but being around so many others that know your breed and will talk to you
will do wonders for your self-education efforts!
5. Study the past history of great dogs in your breed. You will see how your
breed has improved and progressed since the beginning of the breed.
6. Study the breed standard some more! ;-)
7. Join any Yahoo groups about your breed.
8. Live, dream and study your breed.
9. Get a good book on canine reproduction, and educate yourself about the
pitfalls, problems, and proud moments of breeding. Learn about the
physiology of reproduction, such as heat cycles and venereal diseases in
dogs, potential for problems specific to your breed, and what you need to
expect at whelping.
10. Remember that whelping (giving birth) can kill your female. Being used
as a stud dog can encourage bad behaviors common in intact males such as
territorial marking, aggression, and desire to roam from home.
11. Prepare to be broke. Breeding properly is EXPENSIVE.
12. Line up potential homes for any puppies you produce and write up a
contract. Remember to include that you will be willing to take back your
puppies at any time in their lives that they might need you. If you bring
life into this world, it is your responsibility FOREVER.
13. Prepare to spend sleepless nights attending whelping females, caring for
fading puppies or puppies orphaned, and practice cleaning up after 24/7 poop
I'm sure there are many things I missed because being a responsible breeder
isn't just a job. It's a way of life. You will live dogs. 24/7/365. There
are lots of hard decisions. There is a lot of expense. There will be pain.
But, if you do your darndest to always keep the welfare of your dogs and the
future of any of their offspring, you can go to step 14.
14. Enjoy the love and success of a job well done.
Copyright Jennifer T 2007