1: Anatomy of the cell Flashcards
What is histology?
The study of the microscopic structure of tissues
What is a cell?
Basic structural unit of all organisms
What is the most common molecule found in cells?
Water
(on average, 80% of a cell is water)
All eukaryotic cells have an outer ___.
membrane
What is the inner cytosol of a cell?
Solution of proteins, carbohydrates and electrolytes
sol
What structure, made up of filaments and microtubules, determines the shape of a cell?
Cytoskeleton
What is another name for the cell membrane?
Plasmalemma
The plasma membrane has both hydrophobic and hydrophilic elements - what name is given to this characteristic?
Amphipathic
What amphipathic structure is found in the plasma membrane?
Phospholipid bilayer
Name some examples of integral proteins found in the plasma membrane.
Channels
Transporters
Receptors
Enzymes
What is exocytosis?
Movement of material out of the cell membrane via secretory vesicles
What is endocytosis?
Movement of material into a cell via the cell membrane
The phospholipids within the cell membrane move around millions of times per second - this renders the membrane ___.
fluid
The cell membrane is selectively ___.
permeable
What can passively diffuse through the cell membrane?
Water
Oxygen
a few others
Without the action of transporters, what is the cell membrane impermeable to?
Charged ions (Na+, K+ etc.)
Which two types of protein are found in the cell membrane?
Integral (embedded or transmembrane)
Peripheral (fixed to surface)
Which lipid is found in the cell membrane?
Cholesterol
The cytoplasm contains a lot of different structures. What are the two broad classes of these structures?
Organelles
or
Inclusions
Organelles are (essential for life / dispensable).
Inclusions are (essential for life / dispensable).
Organelles - essential for life
Inclusions - dispensable
What happens in the mitochondria?
Aerobic respiration (energy production)
The cytoskeleton is made up of three main classes of filament. What are they called?
Microfilaments
Intermediate filaments
Microtubules
Intermediate filaments
Microtubules
Microfilaments
Arrange from narrowest to widest in diameter.
Microfilaments
Intermediate tubules
Microtubules
Which protein, also found in muscle cells, makes up microfilaments in the cytoskeleton?
Actin
Which protein and its subunits make up microtubules?
Tubulins (alpha and beta)
During mitosis, which structure do microtubules originate from?
Centrosome
Kinesin uses microtubules to move organelles and inclusions towards the cell’s ____.
(centre / periphery)
periphery
Dynein uses microtubules to move organelles / inclusions towards the cell’s ___.
(centre / periphery)
centre
Dynein and kinesin use energy gained from the hydrolysis of ___.
ATP
What is contained within the nucleus?
Chromosomes
Nucleolus (site of rRNA synthesis)
What name is given to the combined inner and outer nuclear membranes?
Nuclear envelope
What is found between the inner and outer nuclear membranes?
What is this space continuous with?
Perinuclear cistern
Rough endoplasmic reticulum
Where are the ribosomes formed before they can be found attached to the RER?
Nucleolus
Why is the rough endoplasmic reticulum rough?
Studded with ribosomes
What is the function of the rough endoplasmic reticulum?
Passes synthesised protein from the ribosomes to the Golgi apparatus for packaging
Cells with lots of RER tend to ___ protein.
export
The smooth endoplasmic reticulum is involved in the synthesis of ___.
lipids
What is the function of the Golgi apparatus?
Modification and packaging of proteins synthesised in the ER
Name the organelles involved in the synthesis, modification and packaging of protein.
Ribosomes
RER
SER
Golgi apparatus
What is the main function of the mitochondria?
Generation of ATP
(From GI: lipid anabolism)
What are the folds in the inner membrane of mitochondria?
Cristae
Mitochondria have their own ___.
DNA
If a cell has a lot of mitochondria, it must require a lot of energy. What does this suggest about the metabolic activity of the cell?
Metabolically active
Lipid droplets, commonly found in adipose cells, are examples of (organelles / inclusions).
inclusions
Which type of junction prevents diffusion between cells by closely binding them together?
Tight junctions / Occluding junctions / Zonula occludens
Which type of junction involves the ‘bolting together’ of cells by microfilaments?
Adherent junctions / Zonula adherens
Name an example of an adherent junction.
Desmosomes
Which type of junction permits selective diffusion of molecules between cells?
Gap junctions / Communicating junctions
An example of a gap junction is that made by ___ proteins.
connexon
