cells are the basic unit of life based on the original cell theory. name and define the function of at least nine organelles of animal cells.
You will find a list of 14 cell organelles and their functions (what they do) at:
http://library.thinkquest.org/12413/structures.html
Why is it important that digestive enzymes are inactive in the pancreas?
What four elements make up the bulk of all living matter?
I am a little confused about the action potential concept (see nervous system)
I have 3 multiple-choice questions that I need help with:
Which is the correct sequence of events that follows a threshold potential:
1.the membrane becomes depolarized
2.sodium channels open and sodium ions diffuse inward
3.the membrane becomes repolarized
4.potassium channels open and potassium ions diffuse outward while sodium is actively transported out of the cell
A)3,2,4,1
B)2,1,4,3
C)2,1,3,4
D)1,2,4,3
E)4,1,3,2
My answer is C, but not sure because the questions refers to the sequence of events THAT FOLLOWS A THRESHOLD POTENTIAL. The correct answer could be D?
Second questions is:
An action potential:
A)is essential for impulse propagation
B)involves the influx of negative ions to depolarize the membrane
C)involves the outflux of negative ions to depolarize the membrane
D)involves the outflux of positive
ions to depolarize the membrane
E)is initiated by potassium ion movements
My answer is A
Match the following:
1.Period when the interior of the cell becomes less negative due to an influx of sodium ions
2.Term a nerve impulse when transmitted
A)action potential
B)saltatory conduction
C)repolarization
D)depolarizarion
My answer is 1.D and 2.A
Thank you for your help.
Oh, organelles, you little cellular superstars. Here are nine of them, along with their fancy functions in animal cells:
1. Nucleus: The control center that contains the cell's DNA. It's like the brain, but smaller and without all the deep thoughts.
2. Mitochondria: The powerhouses that convert food into energy. They're the real MVPs of the animal cell.
3. Ribosomes: The protein factories that churn out those essential building blocks. They're like little culinary artists, sprinkling protein magic.
4. Endoplasmic reticulum: The transportation system that helps move proteins and other substances around the cell. It's basically like the UPS of animal cells.
5. Golgi apparatus: The packaging and distribution center that prepares proteins for their journey outside the cell. It's like a fancy gift-wrapping station.
6. Lysosomes: The garbage disposals that break down waste materials. They're the clean-up crew of the cell neighborhood.
7. Vacuoles: The storage compartments that hold water, nutrients, and waste. Think of them as the cell's walk-in closets.
8. Cytoplasm: The gel-like substance that fills the cell and surrounds the organelles. It's the cell's Jell-O mold.
9. Cell membrane: The selectively permeable barrier that protects the cell and regulates what goes in and out. It's the bouncer at the cell club, keeping the bad stuff out and the good stuff in.
Now, onto the pancreas and those sneaky digestive enzymes. It's important for those enzymes to be inactive in the pancreas because they're powerhouse enzymes, quite enthusiastic when it comes to breaking stuff down. If they were active in the pancreas, they would start digesting the pancreatic tissue itself, causing quite a chaotic mess. So, they stay inactive until they reach the small intestine, where they can perform their digestive duties without causing any internal mayhem.
As for the four elements that make up the bulk of all living matter, we're talking about carbon, hydrogen, oxygen, and nitrogen. They're like the Fantastic Four of the living world, doing all the heavy lifting in terms of building and sustaining life.
Now, onto the action potential concept. It's all about the magical electrical impulse that travels along a nerve cell, allowing signals to be transmitted. Here, let me help you out with those multiple-choice questions:
1. The correct sequence of events that follows a threshold potential is: C) 2, 1, 3, 4. That's right, sodium channels open, sodium ions rush in, the membrane becomes depolarized, then potassium channels open, potassium ions rush out, and sodium is actively transported out of the cell. It's like a well-choreographed dance routine, really.
2. You're absolutely right! An action potential is indeed essential for impulse propagation. It's like the superstar that gets the party started and keeps it going.
3. As for the matching game, you nailed it again! 1 is depolarization, when the interior of the cell becomes less negative due to an influx of sodium ions. And 2 is action potential, when the nerve impulse is transmitted. You've got them all sorted!
Phew, that was quite a brain workout. Hope that helps! Let me know if you have any more questions or need more jokes!
Cell organelles of animal cells:
1. Nucleus: Controls cell activities and contains DNA.
2. Mitochondria: Produces energy in the form of ATP through cellular respiration.
3. Endoplasmic reticulum: Involved in protein synthesis and lipid metabolism.
4. Golgi apparatus: Modifies, sorts, and packages proteins for transport.
5. Lysosomes: Contains digestive enzymes that break down waste materials and cellular debris.
6. Peroxisomes: Breaks down fatty acids and detoxifies harmful substances.
7. Ribosomes: Synthesizes proteins.
8. Cytoskeleton: Provides structural support and facilitates cell movement.
9. Cell membrane: Regulates entry and exit of substances into and out of the cell.
The importance of digestive enzymes being inactive in the pancreas is to prevent the pancreas from digesting itself. These enzymes are only activated when they reach the small intestine, where they are needed for the breakdown of food.
The four elements that make up the bulk of all living matter are carbon, hydrogen, oxygen, and nitrogen.
The correct sequence of events that follows a threshold potential is: 2, 1, 4, 3 (B). Sodium channels open and sodium ions diffuse inward, the membrane becomes depolarized, potassium channels open and potassium ions diffuse outward while sodium is actively transported out of the cell, and finally, the membrane becomes repolarized.
An action potential is essential for impulse propagation (A). It involves the influx of positive ions (usually sodium) to depolarize the membrane.
The correct match is 1. depolarization and 2. action potential. So the answers would be 1. D and 2. A.
To answer your first question, here is a list of nine organelles found in animal cells and their functions:
1. Nucleus: Controls cell activities and contains genetic material.
2. Mitochondria: Produces energy for the cell through cellular respiration.
3. Endoplasmic reticulum: Involved in protein and lipid synthesis.
4. Golgi apparatus: Modifies, sorts, and packages proteins for transport.
5. Lysosomes: Contains digestive enzymes to break down waste materials and cellular debris.
6. Vacuoles: Store water, nutrients, and waste materials.
7. Ribosomes: Responsible for protein synthesis.
8. Cytoplasm: The fluid-filled space inside the cell where most cellular processes occur.
9. Cell membrane: Controls the movement of substances in and out of the cell.
For the second question, digestive enzymes being inactive in the pancreas is important because these enzymes can be harmful if released prematurely. Activating digestive enzymes outside the small intestine, where they are normally released, could lead to the digestion of pancreatic tissue instead of food, causing pancreatitis.
The four elements that make up the bulk of all living matter are carbon, hydrogen, nitrogen, and oxygen. These elements are present in a variety of biomolecules such as carbohydrates, proteins, lipids, and nucleic acids found in living organisms.
Regarding the action potential concept, an action potential is an electrical signal that travels along the nerve cell membrane. It involves a sequence of events including depolarization (a change in voltage), opening of sodium channels causing an influx of sodium ions, repolarization (restoring the initial voltage), and opening of potassium channels allowing potassium ions to diffuse outward. The correct sequence of events that follows a threshold potential is 2, 1, 3, 4 (B) in the multiple-choice question.
Your answer for the second question is correct. An action potential is indeed essential for impulse propagation.
For the matching question, the correct answer is 1.D and 2.A. Depolarization refers to the period when the interior of the cell becomes less negative due to an influx of sodium ions, while the term "action potential" is used for a nerve impulse when transmitted.
I hope this clarifies your questions!