Topic 1 Flashcards
What are the 3 components of the cell theory and what is the purpose of this theory?
- All living things are composed of cells
- Cells are the smallest unit of life
- Cells come from pre-existing cells
Explain an example of an emergent property that arises in the body.
Cellular components interact so that the organism can carry out a range of more complicated functions.
Ex. Cells form tissues, tissues form organs, and organs form systems.
Describe an example of cells undergoing specialization in the body, and for what purpose.
The expression of some genes from the organisms genome in the cell, but not others
This process produces cells for a specific purpose.
What is the relationship between surface area and volume in cells?
Volume: Determines the level of metabolic reactions
SA: Determines the rate of exchange of materials with the outside environment
As volume increases so does SA but not in the same proportion
Explain how stem cells would help a patient with
Stargardt’s disease.
Stem cells are injected into the retina
The number of cells then increases
These cells replace the damage cells with new ones.
Why might stem cells be considered pluripotent?
Because they can become any cell type.
What are the limitations of adult stem cells?
- Difficult to obtain, very few are available
- Some tissues contain no adult cells
- Differentiate into fewer cell types.
In what ways are eukaryotic cells more complex than prokaryotic cells?
Prokaryotic cells are more simple. Less internal components with no compartmentalization.
What is the difference between prokaryotic DNA and eukaryotic DNA?
Prokaryotic DNA: A single circular chromosome
Eukaryotic: DNA is found in the nucleus (A closed membrane). Linear chromosomes.
Explain the process of binary fission in prokaryotic cells.
When prokaryotic cells split themselves from one cell into 2.
Explain 3 structures and their functions in a eukaryotic cell.
Mitochondria: is where the ATP of the cell is produced. Enclosed by a double membrane
Ribosomes: Small structures that build protein molecules, not enclosed by a membrane.
Plasma membrane: Controls movement of materials in and out of the cell.
Suggest why the heads and tails of phospholipid molecules are oriented the way they
The head of the phospholipids is hydrophilic (attracted to water). While the tail is hydrophobic, (repelled by water.
Why are phospholipids considered “amphipathic”?
Because it has polar, and non-polar areas.
Simple diffusion
Move small nonpolar molecules from a high concentration to a low concentration.
Facilitated diffusion
Larger polar molecules moving from a high concentration to a low concentration through the assistance of an integrated protein channel.
Osmosis
The movement of water from a low solute concentration to a high solute concentration. Assisted by aquaporins (Integral protein)
Hypertonic
High concentration of solute outside of the cell. Water will diffuse outside of the cell
Hypotonic
Low concentration of solute outside of the cell. Water will diffuse into the cell
Isotonic
Equal amount of solute inside and outside of the cell.
Sodium - Potasium Pump
- Neurons need a gradient of high concentrations of sodium on the outside and high concentrations of potassium on the inside.
- 3 sodium ions bind to the internal sites of the pump
- ATP is used to alter the shape of the protein channel and move the sodium to the outside of the cell.
- This alteration opens 2 sites for potassium to bind
- The phosphate group is released from the protein causing it to go back to its original form, releasing sodium into the cell.
What is the potassium-sodium ratio?
3 sodium to 2 potassium moved via the pump.
Bulk transport
The movement of large amounts of particles into and out of the cell. (Uses ATP)
Endocytosis
Taking a large sum of particles into the cell
- The membrane folds into itself trapping the solution
- Substance is enclosed by phospholipids (vessicle)
Exocytosis
The release of large amounts of particles to the outside of the cell.
- Vesicle fuse with the membrane
- Push the internal content to the outside
Mitosis
The mother cell splits creating 2 genetically identical daughter cells.
Interphase
4 stages
- Gap 1 = normal functions, growing
- Synthesis = DNA gets replicated
- Gap 2 = Normal functions, prepares for cell division
- Gap 0 = No division is happening
Prophase
- Nuclear membrane breaks down
- DNA condenses into chromosomes
- Spindle fibers begin to form
Metaphase
Chromosomes are lined to the center of the cell through spindle fibers.
- Spindle fiber attaches to the centomers.
Anaphase
Spindle fiber pulls the sister chromatids.
Telophase
Spindle fibers break down and a new nucleus begins to form.
Cytokinesis
The splitting of the cell
Cyclins
A protein that controls the division of the cell.
Cancerous cell
The uncontrolled cell division
Mutagen and examples
A cancer-causing agent that alters the DNA of an organism.
- Xrays
- Arsenic
- Viruses
Oncogene
If a mutation occurs on an oncogene it can cause cancer.
Mutation
Is a change in an organism’s genetic code (DNA).
Metastasis
The spread of cancer from its original location to other places in the body.
