Cells 1.1 Cell structure Flashcards
Give an exceptions of the cell theory.
Giant algae (mermaid’s wineglass) The entire organism is made from only 1 cell that can reach to 7cm. The orgasm is not divided into smaller cells. Aseptate fungus Many fungi are aseptate, this means that the cell walls that divide the cells have broken down. The cytoplasm is continuous with many nuclei. Skeletal muscles Cells fuse together to form muscles fibers. It is impossible to tell where one cell ends and next begins. Slime mold They reproduce when many cells fuse together to form a multi nucleate jelly.
How can you calculate magnification?
(image size)/(actual size)=magnification
What are the three statements of the cell theory?
- All living organisms are made of cells 2. A single cell is the smallest unit of life 3. Cells come from the division of pre-existing cells.
What is the thickness of plasma membranes?
7-8 nanometers
What is the size of a liver cell?
30 micrometers
What is the size of a plant cell?
50 micrometers
What is the size a amoeba?
1000 micrometers
What is the size a amoeba?
1000 micrometers
How many mm in 200 micrometers?
0.2 mm
How many micrometers in 10 mm?
10,000 micrometers
How many nm in 2 mm?
2,000 micrometers = 2,000,000 nm
How many micrometers in 0.8 mm?
800 micrometers
How many mm in 5 micrometers?
0.005 mm
How many micrometers in 23.4mm?
23,400 micrometers
How many micrometers in 23.4mm?
23,400 micrometers
What are the 7 factors that qualify something to be alive?
Nutrition, metabolism, growth, response, excretion, homeostasis, reproduction.
Briefly explain metabolism.
All organisms are sustained by chemical reactions that take place inside their cells, including respiration to release energy.
Briefly explain homeostasis
Keeping conditions inside the organism within tolerable limits. (Release Sweat and shiver)
As the volume of a cell increases, what happens to heat production?
Heat production increases.
As the volume of a cell increases, what happens to the production of waste products?
The production of waste products increase.
As the volume of a cell increases, what happens to the usage of nutrients and oxygen?
The usage of nutrients and oxygen increases as it demands more.
As the volume of a cell increases, what happens to the surface area to volume ratio?
The surface area to volume ratio decreases as volume increases.
Why can a cell not grow to the size of a football field?
- As the volume increases, heat production significantly increases while surface area is not enough to balance heat loss, causing the cell to overheat. 2. As volume increases waste production increases while the surface area to volume ratio decreases, waste excretion is harder. 3. As volume increases, resource consumption directly increases, while resource absorption does not increase as much, causing a limitation towards absorption.
Suggest three features of a cell that could increase surface area.
- In the small intestine, microvilli increase surface area. 2. Plant roots increase surface area for absorption of nutrients. 3. Red blood cells have a donut shape which increase surface area.
What is an emergent property?
Emergent properties arise from the interation of compnent parts: the whole is greater than the sum of of its parts
What is specilization in cells?
Different cells are dedicated to carrying out different functions. Specilized cells have their own structures to enable them to perform their roles
What do motor neurons do?
Is responsible for carrying out electrical signals over long distance
What do red blood cells do?
Thye are responsible for the transportation of oxygen.
What is a stem cell?
Stem cells are the primary cells that are undifferentiated
Have the capacity to differentiate themselves
What does it mean when cells differentiate?
When cell differentiate, they become specialized cells.
To become speialized cells, they turn off unnecessary genes
What is necessary for embryonic development?
The capacity of stem cells to divide and differenciate along different pathways.
This makes them suitable for treatments.
What diseases can be treated with embryonic stem cells?
Heart failure
heart muscles are usually damaged so adult stem cells can be used to replce in order to repair damamged heart muscles.
Umbiblical Stem cell
Faconi anaemia is a blood disease that can be treated using umbiblical stem cells.
What properties do multicellular organisms have?
properties that emerge from interaction of their cellular components (known as emergent property). Basically many different specialized cells that work together
What causes cell differentiation in multicellular organisms?
The expression of some genes but not others
