1,2-Cell Structure Functions 1,2 Flashcards
Which are the single cell organisms(microorganisms)
Bacteria
Archea
Yeast-Fungi
What is prokaryotic cells main characteristic (give one example)
cells without membranebound structures (and a membrane bound nucleus)
For example: Bacteria
Name some characteristics of bacteria cells
- Typically a few micrometres in length
- Variety of shapes(from spheres to rods and spirals)
- One of the first live forms to appear on Earth(they have been around for 3,5 billion years) and since then they are present in most of its habitats
- Bacteria cells in human flora are 10 times as many human cells in body
- The largest number of bacteria is in the gut flora and just a large number is on the skin
- Weigh 10 εις την -12 g and divide every 20 minutes.
Where are the most bacteria cells located in the human body?
They are located in the gut flora
How much is the bacteria cell’s weight?
It is 10 εις την -12
How much time is required for a bacteria cell to be divided?
Around 20 minutes
What is archaea?
- They are single-cell microorganisms
- Prokaryotic, meaning that they do not contain a nucleus or membrane-structured organelles
- They were first found in extreme environments, such as volcanic hot springs
What is Fungi?
- They are eukariotyc organisms
- They are sympionts meaning that to survive they need to live IN,ON or sometimes NEAR its host (plants,animlas, other fungi or parasites)
What is the function of fungi?
Fungi perform an essential role in
the decomposition of organic matter and have
fundamental roles in nutrient cycling and
exchange in the environment
Which ‘class’ of cells have bigger diversity eukaryotes or prokaryotes?
Prokaryotes have abigger diversity
Up to which magnitude can we see with:
- Our eyes?
- A light microscope?
- With an electron microscope?
eyes: up to 0.2 mm
light microscope: up to 200 nm
electrone microscope: up to 0 .2nm
What is Golgi?
Golgi is an organelle responsible for packing molecules like proteins and lipids
What is Peroxisome and which is its function?
Peroxisome is a small organelle that contains
- the enzyme oxidases(generates hydrogen peroxide {H2O2] )
- some catalase, which degrades hydrogen peroxide to water and oxygen
Main function is
- breaking down many different molecules
- Produce acetyl groups that are used in the production of cholesterol and biosynthetic molecules in animal cells
- Degrade toxins produced by liver,kidney cells etc.
What is lysosome?
Lysosome is an organelle in the cytoplasm of EYKARYOTIC CELLS containing degradative enzymes enclosed in a membrane
Do prokaryotic cells contain lysosomes?
No they are present only in eukaryotic cells.
Why we use the definition ‘Cell Type’?
We use this classification in order to distinguish between morphologically and phenotypically distinct cell forms within species
Does the shape and the size of the cell relate to its function?
Yes of course it does.
Where a ‘Cell Wall’ can be found and which its functions?
A cell wall can be found in plants,algae,fungi and MOST bacteria
- It protects the cell
- It gives shape
Do eukaryotic cells have membrane-bound structures?
In what kind of organsisms can they be found?
yes
They can be found in: animals,plants,fungi, protists
Cell Membrane: Can be found in all cells? Where is it located? Which are its functions? Which is its structure?
protective layer around ALL cells
• For cells with cell walls,the cell membrane is inside the cell wall • Allows food, oxygen, & water into the cell & waste products out of the cell. -Sperates cell from the outside -Recognises signals from other cells(allow communication between cells)
- Double layer of fat(phospholipid bilayer)
- It has receprot molecules(proteins)
How can we compare two cells?
By observing their shape and size
Cytoplasm:
Where is it located?
What is its structure?
What is its function?
inside cell membrane
gelatin-like
Flows continuously
What does the protoplasm contain?
It contains the cytoplasm and the nucleus
Cytoskeleton:
Where is it located?
What is its structure?
What is its function?
- scaffolding-like structure in cytoplasm,is a network of fibers (protein) extending throughout the cytoplasm
- Provides structural support(maintains shape) to the cell and also helps in cell motility and regulation (organizes the structures and activities of the cell).
Which are the main fucntions of the Nucleus?What about its size?
-Directs all cell activities
- Contains instructions for
everything the cell does
-Protects DNA, which has instructions for building proteins
It is usually the largest organelle
What kind of molecule does the nucleus contain?Is it hereditary?
DNA, yes it is hereditary
What are the functions of the Nuclear Membrane?
-separates nucleus from cytoplasm - controls movement of materials in & out of nucleus through specific polls
Nucleolus:
Where can be found?
Which are its function?
What is it (generally)?
- Found in the nucleus
- Site for ribosomal RNA
- It is a little nucleus
Chromatin:
What is it composed of?
What does it contain?
- made of DNA & proteins
- contains genetic code that controls cell