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
What is mtDNA
mitochondrial DNA
Mitochondria:
As we know mitochondria are oragnelles that produce energy:
-Where does this energy come from?
-How this energy is being released?
-Which cells have way many mitochondria and how many?
-What they are composed of?
-Organelles that release energy from food - This energy is released by breaking down food into carbon dioxide - Some muscle cells have 20,000 mitochondria
-They are composed of a double membrane (inner and outer)
Endoplasmatic Reticulum
What are they consisted of?
With what can we compare it to?
-A series of folded membranes that move
materials(proteins) around in a cell
- like a conveyor belt
How many types of ERs are present in human cells and which is their distinct functions?
They are 2 types of ERs:
- Smooth ER
- Rough ER
Smooth ER – ribosomes not attached to ER
• Rough ER – ribosomes attached to ER
What makes an ER rough?
The ribosomes that are attached to it.
Ribosomes:
WHich is their function?
Where they can be located?
Where they be formed?
-Make proteins
• Float freely or attached to the endoplasmic reticulum (ER)
• Ribosomes are made in the nucleolus
Golgi Bodies:
What they are made of?
Which is their function?
How is it divided?
Where do the vesicles fuse when arriving from the ER?
After movement through the Golgi, from which part are the bud oof?
Stacked flattened
membranes
• finishes, sorts,labels and ships proteins( works as a headquarter)
Ships proteins via vesicles(they work as UPS trucks)
It is divided in cis-,medial- and trans- Golgi
They fuse with the cis side
They bud off the trans- side
In which type of cells can golgi bodies be found (eukaryotic/prokaryotic, plant cells/ animal cells)?
They can be found in both animal and plant cells but only in eukaryotic ones.
What are vesicles and vacuoles?
Which are their functions?
Which is their structure?
Moving material around cell
Temporary storage spaces for food, water, waste
They are made of a membrane sac
Which are functions of lysosomes? Which is their structure? Some special remarks about them? What kind of molecules do they contain? How many can we found in a typical animal cell? How lysosomes are 'destroyed'?
- It digest things in order to make energy and to cleanup the cell and recycle molecules
- Break down food molecules
- Breaks down the cell when it dies
Membrane sac of digestive enzymes.
They are acidic organelles (pH=4.8)
They contain degradative enzymes (acidic hydrolases):nucleases, proteases, phosphatases
They can be several hunderd lysosomes in a typical animal cell
They degradate themselves through a process that is called autophagy
In which categories can prokaryotic cells be calssified?
Bacteria
Archaea
Bacteria: Are they multi-cell organisms or single-cell? How they divide? What their cell walls consist of? What they use for energy?
- They are single-cell organisms
- They are divided by binary fission
- They consist of peptidoglycan walls
- For energy the use organic chemicals and inorganic chemicals OR the produce energy via photosynthesis
Where the genome is held in a prokatyotic cell?
The genome in a prokaryote is held within a
DNA/protein complex in the cytosol called the
nucleoid, which lacks a nuclear envelope.
Can the way in which bacteria and archaea are multiplied to b characterised as a replicative process?
No it cannot.
Plant cells:
What kind of cell are they?(eukaryotic/prokaryotic)
What is the difference between them and other kind of cells(non-plant cells)
They are eukaryotic cells
They differ form other eukaryotic cells because they have a large vacuole
What is a vacuole? Which are its functions?
It is a membrane-bund structure which is filled with water, more specifically:
- Maintains cell’s tugor
- Controls the movement of molecules between the cytosol and sap
- Stores useful material
- Digests waste proteins and organelles
Which part in plant cells is the most notable?
Platids are the most notable beings in plant cells as they are pigmented. They contain chlorophyl which is a green-coloured substance.
Where can chlorophyl be found and which is its function?
Chlorophyl can be found in plastids, it is a green-coloured substance which absorbs sunlight and allows the plant to make its own food through a process that is called photosynthesis.
What cell wall consists of?
Cell wall consists of: Cellulose hemicellulose pectin and in MANY cases lignin
Where plastids are located in a plant cell?
Plastids are located inside chloroplasts
What’s the structure of a virus?
-Consist of DNA or RNA core
-> Core is surrounded by a protein coat
-> Coat may be enclosed in a lipid envelope
-> Viruses are replicated only when they are in a
living host cell
-> Not cellular
How can ‘Cell Death’ be called?
Apoptosis
WIth which techniques do we study cells and how are they been conducted?
▪Microscopy (technique when microscopes are used)
▪Cell Fractionation (Through this technique we disrupt the cell and isolate the diffeernt type of cell organelles in order to stydy them)
How can microscopy be divided?
- Light microscopy(no less than 200nm)
- Electron microscopy(no less than 0,2nm)
Which are the cells main jobs?
Make energy,
for all activities they do
To clean up waste produced while makinh energy
Make proteins,
Proteins do all the work in a cell, so we need them
Make more cells
For the organism to grow
To replace any damaged or diseased cells
What is autophagy (autophagocytocis)?
Is this procedure important for cells?
• Autophagy , is the natural, destructive
mechanism that disassembles, through a
regulated process, unnecessary or
dysfunctional cellular components.
Autophagy is an omiostatic mechanism for cells.
Through which process do mitochondria make ATP?
Which is the reaction?
They make ATP energy through cell respiration
sugar + O2 = ATP
Which organelles contribute to protein production?
nucleus
ribosomes
endoplasmatic reticulum (ER)
Golgi apparatus
What kind of membrane is the nuclear composed of (double or single?
double membrane(inner and outer)
What is the function of Endoplasmatic Reticulum (ER)
- Helps complete the prteins after the ribosomes built them
- Makes membranes
What is the function of smooth ER and rough ER respectively?
- Makes membranes enzymes and lipids
- Makes proteins
Which is the function of ribosomes and where can they be found in a cell?
What is made of?
What is composed of?
-They are protein factories
- Some are free to cytoplasm
- Some are attached to ER (and make ot rough)
A ribosome is made from complexes of RNAs (rRNAs) and proteins and is therefore a nucleoprotein
A ribosome is composed of 2 subunits
Small subunit= mRNA pattern sticks to it
Larger subunit=Amino acids , tRNAs stick to it
What happens to the subunits of a ribosome when it finishes reading the mRNA?
When ribosome finishes reading the mRNA, the two subunits split apart.
Is hydrogen peroxide good for our health?
No
Is oxidation linked to ATP generation?
No
Are centrioles present in all type of cells?
Why the other type f cell do not have centrioles?
What is the function of Centrioles?
How many are there in each cell?
No, they are present only in animal cells.
Plant cells do not need them
They help coordinate cell division
There is a pair in each cell
Mitochondrial diseases. How they occur? Which are the consequences? Which are the symptoms?(13) What other causes might mt diseases?
- MtDNA mutations are thought to be responsible for this kind of diseases.
- These diseases cut off the mitochondria (cell’s energy supply)
-Poor growth • Loss of muscle coordination, muscle weakness • Visual or hearing problems • Developmental delays, learning disabilities • Mental retardation • Heart, liver, or kidney disease • Gastrointestinal disorders • Respiratory disorders • Diabetes • Increased risk of infection • Neurological problems, seizures • Thyroid dysfunction • Dementia
-DNA inheritance
• MtDNA inheritance
• Combination of mtDNA and nDNA defects
-Random occurrences
What is nDNA
Nuclear DNA
Which are the treatments for mitochondrial diseases?
Are they considered to be absolutely effective?If yes in which levels?
Certain vitamin and enzyme therapies
-Vitamin therapies:such as riboflavin,
-enzyme:coenzyme Q,
-carnitine: a specialized amino acid may provide subjective improvement in fatigue and energy levels in
some patients
- Diet therapy
- Antioxidant treatments
How can a lysosomal disease occur?
Any examples?
Characterized by the deficiency of a single
lysosomal enzyme and corresponding
accumulation of undegraded substance
for example these diseases resulting from an acumulation of undegraded sphingolipids.
Name two lysosomal storage diseases
Pompe disease, Tay-sachs disease
Tay-sachs disease: What is the incidence of this disease? What is the cause? Which are the characteristics of this disease? Which are the symptoms?
Incidence: very rare in the general population. 1 in 3600 newborns among Jews of eastern European ancestry
Deficiency of the enzyme β-hexosaminidase A. The ganglioside Gm2 accumulate in the bloated lysosomal of brain cells dysfunction
Characterized: Progressive motor and mental retardation
Symptoms: Skeletal, cardiac and abnormalities
What is Meckel-Gruber syndrome?
What is Tay-sachs disease?
What is Pompe disease?
- It is a lethal ciliopathic disorder where there is an inability of the cells to use centrioles to make functional cilia and flagella.
- They are lysosomal storage diseases
What is the mother centriole?
Which is its function?
It is the basal body
It’s funtion is to determine the position of cilia and flaggela….
