1.1 - Intro To Cells Flashcards
What are the common characteristics that all cells share?
- Cells are surrounded by a membrane
- Cells contain genetic material
- Chemical reactions catalysed by enzymes take place in cells
- Cells have their own energy release system that powers all of the cell’s activities
How do you convert millimetres into micrometers?
Multiply by 1000
How do you convert micrometers into millimetres?
Divide by 1000
Magnification equation :
Magnification = size of image / actual size of specimen
What are striated muscle cells?
The type of tissue that we use to change the position of our body.
Made out of muscle fibres, which are similar to cells - surrounded by a membrane, formed from pre-existing cells, have their own genetic info and energy release system.
How are Striated Muscle Cells atypical cells?
⭐️They are much larger than most animal cells⭐️
- In humans - average length of 30mm
- Other human cells are mostly less that 0.03mm in length
⭐️They have many nuclei⭐️
- Can have up to several hundred
- Human cells only have one
What are hyphae?
Make up fungi
Narrow thread-like structures
Usually white in colour
Have a fluffy appearance
Have a cell membrane and cell wall
Uninterrupted tube like structure with many nuclei
Why are hyphae atypical cells?
They have many nuclei in their long threads
What are algae?
Organisms that feed themselves by photosynthesis, and store their genes inside their nuclei.
But - they are simpler in their structure and organisation than most plants
Why are giant algae atypical?
Can grow to as long as 100mm
But - is unicellular
What are the 7 functions of life that all cells carry out?
Metabolism
Reproduction
Homeostasis
Growth
Response
Excretion
Nutrition
What is the metabolism of a cell?
Large numbers of chemical reactions that take place in the cytoplasm of the cell
The metabolic rate of the cell is proportional to what?
The volume of the cell
What happens if a cells surface area to volume ratio is too small?
Substances will not enter the cell as quickly as they are required - and waste products will accumulate because they are produced more rapidly than they can be excreted
Why surface area to volume ratio is related to heat production and loss?
If the surface area to volume ratio is too small, then cells may overheat because the metabolism produces heat faster than it is lost over the cell’s surface
Define multicellular
Organisms consisting of a single mass of cells, fused together
Define emergent properties
The interaction of the component parts of a complex structure
The whole is greater than the sum of its parts
Define division of labour
In multicellular organisms, different cells perform different functions
Define tissue
A group of cells which specialise in the same way to perform the same function
Function of a red blood cell
To carry oxygen
Function of a rod cell in the retina of the eye
To absorb light and transmit impulses to the brain
Benefits of cell specializing
Cells can carry out their role more efficiently than if they had many different roles
Can develop the ideal structure - with the enzymes needed to carry out all of the chemical reactions associated with the function
Define differentiation
The development of cells in different ways to carry out specific functions
How many distinctively different highly specialised cell types have been recognised in humans?
220
