Transport, cellular metabolism & energy production Flashcards
Describe the function of mitochondria in the cell
Mitochondria are a type of organelle.
Mitochondria use pyruvate and acetylCoA from food to make energy.
The number of mitochondria in cells vary.
ie. In very active cells like muscle cells, there are many but our RBCs have none.
Describe the function of ribosomes in the cell
Make proteins for the cell.
Describe the function of Rough endoplasmic reticulum in the cell
An organelle that surrounds the nucleus and contains ribosomes.
Describe the function of smooth endoplasmic reticulum in the cell
An organelle surrounding the rough endoplasmic reticulum which makes cellular products like hormones and lipids.
Describe the function of golgi apparatus in the cell
An organelle where proteins are mixed with other chemicals and are enclosed in a bubble-like structure that moves toward the cell membrane to release it’s contents.
Describe the function of lysosome in the cell
A type of acidic organelle where food is broken down before it travels to the mitochondria.
Lysosomes also break down worn out parts of the cell and gather waste products for the cytoplasm.
Describe the function of peroxisome in the cell
An organelle in the cytoplasm that breaks down fatty acids and transfers compounds from hydrogen to oxygen.
Describe the function of microtubules in the cell
Microtubules form part of the cytoskeleton. Their main role is to support and maintain the shape fo the cell but they also play a role in transportation.
Describe the function of microfilaments in the cell
Microfilaments are part of the cytoskeleton and assist with cell movement. They also help to keep organelle in place.
Describe the function of the nucleus in the cell
An organelle that contains DNA. It co-ordinates cell activities such as: >Growth >Metabolism >Protein synthesis >Cell division
Describe the function of the nucleolus in the cell
Is inside the nucleus. It’s role is to transcribe RNA and combine it with proteins to form incomplete ribosomes.
Describe the function of chromatin in the cell
The chromatin’s job is to package DNA small enough that it fits into the nucleus and protecting it’s structure and sequence.
Describe the function of centriole in the cell
Organelles that help with cell division.
Describe the function of cilia in the cell
Organelles that project from the cell body.
They use rhythmic waving motions to clear debris for sensory purposes.
Describe the function of flagella in the cell
The threadlike tail on some cells like sperm cells. Their function is to allow those cells to swim.
Describe the function of microvilli in the cell
Organelles that project from the cell body. They use rhythmic waving motions to absorb debris.
Define lateral
To the side
Define medial
Towards the centre
Define proximal
Nearer to the centre
Define distal
Further from the centre
Define superior
Above
Define inferior
Below
Define rostral/cranial
Pertaining to the head
Define anterior/ventral
The front
Define posterior/dorsal
The back
Define coronal plane
A vertical plane that divides the body into front and back sections.
Define sagittal plane
A vertical plane which divides the body into left and right parts.
Understand the abdominal regions
From Left to right, top to bottom: >R hypochondrium >Epigastric region >L hypochondrium >R lumbar >Umbilical region >L lumbar >R illiac region >Hypogastrium >L illiac region
Describe the function of the cytoplasm
The cytoplasm keeps organelles in place and contains everything apart from the nucleus and chromosomes.
It is composed of water, vitamins, chemicals and organelles.
What substance is the primary energy source for mitochondria in human cells?
Glucose
What would happen at the cellular level in a patient with hypoxia?
Results in depletion of ATP in cells that triggers a switch to anaerobic glycolysis. Since the energy yield from glycolysis is much less than from oxidative phosphorylation, energy demands are not met and the continuing decrease in ATP levels results in additional cellular dysfunction.
How does the body try to compensate during hypoxia?
During hypoxia, we see vasodilation, allowing for greater tissue perfusion.
What is the result of long term hypoxia?
> Loss of consciousness
Seizures
Damage to the brain
Cell death/tissue death
What is the difference between rough ER and smooth ER?
Only rough ER contains ribosomes.
What is the function of cells that contain more rough ER than smooth ER?
Cells specialising in the production of proteins will tend to have a larger amount of rough ER.
What is the function of cells that contain more smooth ER than rough ER?
Cells producing lipids (fats) and steroid hormones will have a greater amount of smooth ER.
What types of cells have a prominent golgi apparatus?
The Golgi apparatus tends to be larger and more numerous in cells that synthesise and secrete large quantities of materials; for example, the plasma B cells and the antibody-secreting cells of the immune system have prominent Golgi complexes.
What is the function of cells containing contractile proteins?
Contractile proteins are actin and myosin. Cells that contain more of these may play a role in muscle contraction.
Where are cells with microvilli located?
In the small intestine where absorption of nutrients occurs.
What is the driving force behind passive movement across a cell membrane?
Diffusion
What type of molecules can easily diffuse into or out of cells through the lipid bi-layer?
> Oxygen
Lipids
Lipid-soluble molecules
How do water soluble molecules move across the membrane?
Osmosis - the diffusion of water through a semipermeable membrane down its concentration gradient.
ie. When the pressure inside the cell is less than the pressure outside the cell, water will move in naturally.
How does facilitated diffusion differ from simple diffusion?
Facilitated diffusion requires the use of either channel proteins or carrier proteins to allow substances that can’t diffuse through the phospholipid bilayer, to cross the membrane.
What is the driving force of facilitated diffusion?
Although a carrier protein is involved, the driving force is the concentration gradient.
How is facilitated diffusion selective?
Carrier proteins and channel proteins are selective in that they are only able to transport certain molecules.
eg. The NaK pump will only transport Na and K.
How does osmosis differ from simple diffusion?
Osmosis refers exclusively to the movement of WATER across a membrane.
Diffusion refers to molecules.
ie. Particles and Solutes
Which types of molecules are transported through membranes by facilitated diffusion?
Polar and charged molecules like:
>Amino acids
>Carbs
>Ions
What is the driving force of active transport?
ATP
What is homeostasis?
A state of balance for many things in the body:
>Blood pH
>BGL
>Internal body temp
Explain the differences between positive and negative feedback
Positive feedback intensifies a signal.
eg. During childbirth
Negative feedback triggers a counteractive response to get rid of the signal.
eg. Sweating when you’re hot
What is meant by the term cellular homeostasis?
Any process involved in the maintenance of an internal steady state at the level of the cell.
