Cellular Basis of Life
What is the smallest unit capable of life?
The Cell
What is the plasma membrane primarily made from?
Phospholipids
What is a function of Microtubules?
Cell shape and support
Intracellular transport
Cell division
Cell locomotion
Centrosomes and Cilia
What is simple diffusion?
The movement of solutes from high to low concentration.
What are the three main parts of a human cell?
1. The plasma membrane
2. The cytoplasm
3. The nucleus
Describe the fluid mosaic model of the plasma membrane. Include three details.
Thin structure (7–10 nm)
Double layer (bilayer) of phospholipid molecules
Protein molecules dispersed within the bilayer
What is one thing that would happen if we didn't have peroxisomes?
Fatty acids would not be broken down
hydrogen peroxide would accumulate
ATP production would be impaired
The cell as a whole would be damaged
Mitochondria's health would suffer
What kinds of substances can diffuse DIRECTLY through the plasma membrane?
Small nonpolar and lipid soluble substances diffuse directly through the lipid bilayer.
What are the three parts to modern cell theory?
The cell is the smallest unit of life
All organisms are made of one or more cells
Cells only arise from other cells
What are glycolipids made from? What purpose do they serve (3)?
Lipids with attached sugar groups.
Serves for cell recognition, interaction, and signaling
Besides cell division, what other function do centrioles serve?
Besides cell division, centrioles also contribute to the formation of cilia and flagella, structures that aid in cell movement and sensory functions.
What three factors affect the rate of diffusion?
Molecular size – smaller = faster
Concentration – Higher = faster
Temperature - warmer = faster
Fresh water is a precious natural resource in Florida, and it is said that supplies are dwindling. Desalinizing (removing salt from) ocean water has been recommended as a solution to the problem. Why shouldn’t we drink salt water? 1) What will it cause? 2) Why?
We shouldn’t drink salt water because it causes dehydration.
This happens because the high salt concentration draws water out of body cells by osmosis, making the body lose more water than it gains.
How many different cell types exist in the human body? Roughly how many TOTAL cells make up the human body?
Over 200 different cell types
Trillions of cells in the human body
What is the difference between integral and peripheral proteins? List two functions of each.
Integral Proteins = Inserted into the lipid bilayer
Function = Transport, Carriers, Enzymes, Receptors for hormones
Peripheral Proteins = Not embedded in the lipid bilayer
Function = Attach to cytoskeleton and ECM, Motor proteins, Link cells together
The Mitochondria is likened to the POWERHOUSE OF THE CELL. What is the Golgi Apparatus likened to?
THE POST OFFICE OF THE CELL!!!!
What is facilitated diffusion? What is the difference between leakage and gated channels? What are the three kinds of gated channels?
Facilitated Diffusion = Transported substance bind to protein carriers or are ferried across through protein channels.
Leakage channels are always open
Gated channels are controlled by chemical, mechanical, or electrical signals
A genetic defect causes a person’s desmosomes to form improperly, weakening the connections between skin cells. What clinical symptoms might you expect to observe, and why does this occur based on the function of desmosomes?
The skin cells and muscle cells lose their structural adhesion and separate easily under stress.
What is the primary purpose of the ribosome? List two places they are found in the cell.
Explain the difference between osmolarity, tonicity, AND describe the three kinds of solutions that can exist that affect the cells.
Osmolarity = The total concentration of all solute particles in a solution.
Tonicity is the ability of a solution to change the shape or tone of cells
Hypertonic, Isotonic, Hypotonic
A patient’s sodium-potassium pumps become inhibited due to lack of ATP production from a mitochondrial disorder. How would this affect the resting membrane potential of their nerve cells, and what symptoms might you expect to see as a result?
Sodium (Na⁺) will begin to build up inside the cell and potassium (K⁺) will leak out. This makes the inside of the neuron less negative. Nerve cells can’t properly send or reset nerve impulses. Clinically, you might expect to see symptoms such as muscle weakness, fatigue, confusion, or paralysis,