Cells and cellular level Flashcards
What is a cell
smallest unit of living things: consist of different components to help the cell function these are called ORGANELLS
What is a Epithelial tissue
A layer (or layers) of cells that covers the organs.
Protects the organ from the external environment, but also has a role in secretion (e.g.: mucus, saliva, enzymes) and absorption (e.g.: oxygen, nutrients)
What is Muscle tissue and name the 2 motions caused
made of proteins actin and myosin. the fibres CAN contract generating a force to create motion
Voluntary motion (locomotion, speech etc.) is produced by skeletal muscle.
The beating of the heart is controlled by cardiac muscle.
Involuntary internal motion (contraction of blood vessels, peristalsis: stomach and intestine churning, ejaculation etc.) is controlled by smooth muscle.
We will learn more in the musculoskeletal lectures
what is nervous tissue
Allows control and coordination of other organs by sending signals down neurons.
where is the nervous tissue located
Nervous system / brain/ nerves/ spinal cord
what is connective tissue
Provides shape, structure and support to organs.
Collagen, adipose (fat), cartilage, bones and blood are all examples of connective tissue.
what is mitochondria
it is the powerhouse of the cell responsible for cellular respiration
What is ATP
Adenosine Triphosphate
Energy molecule / created through cellular respiration
Describe what a protein is on a chemical level
The specific shape a protein has is affected by the conditions its in like temperature and pH.
what happens if conditions are not ideal for a protein
the shape shape will change slightly, and it won’t be able to perform it’s function as well.
example is enzymes.
If they become too different from ideal, the protein will change shape so much that it cannot perform its function at all.
it’s called denaturing, and it is irreversible.
chemical level of fats and oils
Made of lipids (including cholesterol and saturated fatty acids)
Make up the plasma membrane of all cells ie: their outside layer or “skin”
Fat tissue (adipose) surrounds and pads organs to protect them and helps trap heat under the skin (insulation).
A major class of hormones are the steroids, which are all lipids (oestrogen, testosterone)
The chemical level : Carbohydrates
Made up of many monosaccharides (sugars) joined together.
Key examples are glucose, galactose and fructose
what is the use of Glucose
Main fuel for respiration to produce energy e.g ATP molecule
cellular respiration
in Mitochondria uses ‘fuel’ e.g glucose burns to produce ATP
Describe Aerobic respiration
Glucose + O2 –> H2O + 30-38 molecules of ATP
This is the good equation = lots of energy for the body
Anaerobic respiration
Lack of oxygen in the body
Glucose –> CO2 + H2O + 2 Molecules of ATP + Lactic acid (lowers PH)
Bad equation
List the order of oxygen perfusion
Ischemia
Injury
Infarction
Necrosis
What is Ischemia
Insufficient oxygen for the cells in the tissue to produce as much ATP as required to function completely normally.
What is Injury in O2 perfusion
Prolonged ischemia causes the cells in the tissue to become injured and stop functioning normally.
These injures can be reversed depending on the length and severity of the ischemia.
What is Infarction in O2 perfusion
If injured enough, the cells of the tissue will die – unable to perform their function. This is called infarction and is irreversible.
What is Necrosis
Cells that die by infarction die by necrosis. If enough cells die this way, parts of the tissue itself can become visibly necrotic.
usually Black or a very dark grey
What is Homeostasis
means physiological processes that act to maintain a stable internal environment in the body.
What is Homeostasis controlled with
Feedback loops
These can be Negative or positive feedback Mechanisms
Feedback loop require 3 parts what are they
Receptors - detects change
Control centre - Usually brain it receives a communication from the receptor and outputs a signal to the ….
Effector - causes a response. THIS acts to either Negative or positive
what is a positive feed back loop
reinforce the change in the condition
what is a negative feedback loop
Try to return the condition to the set-point
