Module 2 Chapter 3 Study Guide Flashcards
Why do cells have to be small in order to function?
Surface area is a factor, surface area is the total area found in the surface of an object. Cells must first cross over this surface area to get nutrients. Being small allows them to do this quickly.
Explain how the surface area to volume ratio limits cell size.
If cells were large it would take too long to get the nutrients they need. By staying small they keep a small surface area:volume ratio so materials can quickly diffuse in and out of the cell.
State the basic principles of the cell theory
- All living organisms are composed of cells
- All cells come from preexisting cells
- Chemical reactions take place within cells
- All cells contain hereditary information
What is the difference between growth and development.
Growth is physical characteristics like height or weight and development is all the changes from fertilization till death
What is metabolism
All chemical reactions that happen in the body
What is an organelle
Structure within a cell that has a specific job or function
Function of the nucleus
This holds genetic instructions for making proteins that help cellular functions
Function of the nucleolus
Produces ribosomes
Function of ribosomes
Ribosomes are the site for proteins systems. Makes all the proteins for the cell
Function of mitochondrion
The site for cellular respiration. Provides the cell with energy by breaking down glucose to make ATP
Function of lysosomes
Vesicles that help break down molecules into smaller pieces.
Function of the rough endoplamsic reticulum (RER)
Responsible for making proteins for the cell
Function of the smooth endoplasmic reticulum (SER)
Synthesizes lipids
Function of the Golgi apparatus
It modifies proteins and lipids. It processes, packages, and secretes. They take into proteins and change them so it can leave the cell in a vesicle
Function of centrioles
Organize microtubules that give the cell its shape
Function of vesicles
Sacs used for transport, they bring things in and out of the cell.
Function of DNA
Contains the specific information needed for the cell to carry out specific functions
Function of RNA
Template for all the proteins in the cell, copy for specific instructions
Function of nuclear pores
Holes that are in the nuclear envelopes that let substances in and out of the nucleus
Can a cell function without all of those organelles ? Explain your answer
All of the function of the cell are linked together so I do not think it could survive with missing even a couple
What is necessary for simple diffusion to work?
Requires movement of a substance from a region of higher concentration to a region of lower concentration
How is diffusion different from osmosis?
Osmosis moves across a membrane where diffusion moves from an area of higher concentration to an area of lower concentration
Upon what is the rate of diffusion dependent (there are a few things)
Surface area, solute, and the gradient
How do large molecules get in and out of the cell
Bulk transport, endocytosis and exocytosis
What does it mean for a meme brand to be selectively permeable?
It is selective on what it lets into the cell
Define osmosis in a cell
The movement of water molecules across a semi permeable membrane.
Define the term solvent, solute, and solution
- Solvent- substances that can dissolve other substances
- Solute- a dissolved substance
- Solution- mixture of a solute and a solvent
What does tonicity mean
The concentration of solute in solutions on opposite sides of a cell membrane
How does the tonicity relate to the direction of water movement across a membrane?
Water will always move in the direction that has more solute. Higher tonicity is higher concentration
What is crenation and hemolysis
- Cremation is when a cell is in hypertonic solution and the water moves out of the cell causing it to shrink.
- Hemolysis is when the blood cell ruptures from a hypotonic solution
Define isotonic, hypotonic, and hypertonic using a red blood cell example
- Isotonic- concentration of solutes is the same inside and outside of the cell. If the solution is 0.9% salt the solution is isotonic to red blood cells
- Hypotonic- concentrations of solutes is lower on the outside than on the inside. Any solution less than 0.9% salt the solution is hypotonic
- Hypertonic- concentration of solutes is higher on the outside than in the inside. Anything over 0.9% salt would be hypertonic to red blood cells
Why do human cells need to live in an isotonic environment
So they do not shrink or rupture
Why do plant cells need to live in hypotonic environment?
Their cells are more rigid and won’t burst
Why does the surface of intestines and the brain have so many folds?
It’s our bodies way of utilizing surface area:volume ration. The small intestine absorbs nutrients from the food we eat. To increase the surface area the small intestines have villi. With the brain it has folds to increase surface area and we are able to make more connections in our neurons
Distinguish between the structure of a prokaryotic cell and that of a eukaryotic cell
- Prokaryotic- lack nucleus, does not contain any membrane bound organelles, smaller in size, unicellular
- Eukaryotic- has nucleus, has membrane bound organelles, larger, DNA twisted strands
Both have plasma membranes, cytoplasm, DNA, and ribosomes
Explain how eukaryotic cell could have evolved from prokaryotic cells
The nucleus could have formed formed by invagination of the plasma membrane come cells bay have arisen by engulfing prokaryotic cells they were not digested but evolved into different organelles (mitochondrion)
How does a membrane regulate its size
Endocytosis- removed lipids
Exocytosis- adds lipids
Describe the structure of the plasma membrane and list the types of molecules found in the membrane
The plasma membrane is made up of a phospholipid bilayer
Hydrophilic polar heads that faces water and two hydrophobic non polar tails that face inwards towards each other
Intrinsic proteins that serve as channels and extrinsic proteins that serve as communication
Why can’t you survive drinking straight seawater?
Become of so much salt the kidneys would receive too much damage and not be able to function properly
What would happen to homeostasis if the body no longer produced enzymes?
Necessary chemical reactions would not take place
