Module 1 Lecture 2 - Cell Structure and Function Ctd. + Cellular Metabolism Flashcards
Why is the mitochondria considered a “power plant” of the cell?
Because it extracts nutrients from the food our body processes and transforms it into usable energy
What are the three components of the cytoskeleton
Microtubules, Microfilaments and Intermediate filaments
How are the three components of the cytoskeleton compared?
Often through the size of each one
What role does the cytoskeleton serve?
Network of protein filaments; allows cell to change shape and help with cell movement & organizing cytoplasm
What is the cytoskeleton often referred to as?
Bone and muscle of the cell - provides structural support to the cell
What are microtubules?
Long, slender, hollow tubes made of this subunit called tubulin; and have this asymmetric cell shape and coordinate complex cell movements
How do microtubules coordinate cell movement
Acting as a highway to allow secretory vesicles to move within a cell
What are the molecules dynein and kinesin used for?
Help transport vesicles through the microtubule highway
Example of microtubules coordinating movement in a neuron
Microtubules abundant in neurons; occupy axons and help facilitate transport of vesicles
What other roles do the microtubules play other than acting as a highway?
Positions cytoplasmic organelles (ER, lyosomes, Golgi, etc), Assemble into mitotic spindle (separates chromosomes), main structural component of cilia and flagella
What are microfilaments?
Intertwined helical chain of actin molecules; smallest protein compared to the three components of the cytoskeleton
Are microfilaments made of myosin too?
Only really in muscle cells - hence muscle contraction
What vital role do microfilaments have?
Utilized in cellular contractile systems (muscle contraction & amoeboid movement) cell shape change & mechanical stiffener for microvilli
What is amoeboid movement and how do microfilaments play a role
Amoeboid movement is referred to as cell movement and microfilaments help change the shape and move around
Example of amoeboid movement
An immune cell uses amoeboid movement to squeeze through gaps
How do microfilaments act as mechanical stiffeners for microvilli?
It helps expand the stomach to absorb more food and prevent it from falling out
What are intermediate filaments?
In terms of size, in between microtubules and microfilaments.
- irregular, threadlike proteins that are extremely strong
Purpose of intermediate filaments
Providing support to the cells and withstanding mechanical pressure and tension
An example of an intermediate filament
Keratin; found in hairs and nails which makes it hard to tear when tension is applied
What is the cytosol also known as?
Cell gel
Why are cytosol and cytoplasm not the same?
Cytosol is the cell gel while cytoplasm is the cell gel + organelles
What’s found floating around in the cytosol?
Protein (enzymes), gel, water, fluids
What 3 things happen in the cytosol
Intermediary metabolism enzymes are dispersed in the cytosol (facilitating intracellular reactions) , transport, secretory vesicles and inclusions
How are transport, secretory and endocytic vesicles connected to cytosol?
The vesicles are apart of the cytosol moving through them and transporting different molecules
What are the inclusions in the cytosol?
nutrient storages; stores excess glycogen and fatty acids for future metabolic processes
Define intermediary metabolism
The sum of all intracellular chemical reactions to break, build or transform organic molecules like simple sugars and fatty acids into energy requiring thousands of enzymes
What organelle does intermediary metabolism take place?
Cytosol
What is energy used for in the cell?
- used for cell activities
- maintain cell structure, function, and growth
Two processes of intermediary metabolism that are known for synthesis and degradation
Anabolic (synthesis) & Catabolic (degradation)
ATP is required to do what?
Making or breaking a protein or molecule
What does ATP look like? More specifically how is it structured?
One adenosine base, three phosphates added to the base
What’s unique about the phosphates when they’re being added to the adenosine base
The more you add; the higher amounts of energy each one carries - third phosphate has the most energy
What are other ways of producing ATP other than the breakdown of food?
Creatine Phosphate, Anaerobic Glycolysis, Aerobic Glycolysis
How does anaerobic glycolysis work?
Through glycolysis it makes a minimal amount of ATP only because it does not use oxygen - hence anaerobic
Without a mitochondria can cells still produce ATP?
Yes; Glycolysis happens in the cytosol so ATP is formed but it’s not enough energy to keep the cells going
Which system makes the most ATP?
Aerobic Glycolysis
How is Aerobic Glycolysis different from Anaerobic?
Includes the use of the mitochondria and other stages such as Krebs and ETC; also the use of oxygen
When is Creatine Phosphate commonly used?
In cells that need a lot of energy and need it quickly
Why would cells need CP so quickly?
In a life or death situation where you have expended a lot of your ATP, CP will come in and provide the substrate needed to rapidly produce ATP and give the organism (us) energy to keep moving
How is creatine phosphate used to make ATP
When the cells have a rapid need for energy and there is hardly any ATP, CP will offer up it’s phosphate to ADP molecules.
What enzyme is required for CP +ADP => C + ATP
Creatine Kinase
Where is Creatine Phosphate stored?
Cytoplasm
Do muscle cells use CP
CP is in fact used in muscle cells, but it is stored for emergency purposes
When happens when the ATP reaches its threshold? (Too much ATP produced)
When your body reaches a certain threshold of ATP, the phosphate gets transferred to Creatine making CP and storing it.
How much more CP than ATP is stored when resting
When the body is at rest, it stores 5x more CP than ATP
How much ATP does 1 glucose grant?
32 ATP in total
