THE CELL AND ITS FUNCTIONS and HOMEOSTASIS Flashcards
This is the Basic living unit of the body
Cell
The entire body contains about ______ cells
100 trillion
BASIC CHARACTERISTICS OF CELL:
- Need Oxygen
- Innate chemical mechanisms to change nutrients into energy
- Almost all cells have ability to reproduce cells of own kind
BASIC STRUCTURE OF THE CELL
TWO MAJOR PARTS:
Nucleus
Cytoplasm
The Nucleus is separated from cytoplasm by ______.
nuclear membrane
The Cytoplasm is separated from the surrounding fluids by ______ also called as the ______.
cell membrane, plasma membrane
MEMBRANOUS STRUCTURES OF THE CELL:
- Cell Membrane
- Nuclear Membrane
- Membranes of Organelles:
Endoplasmic Reticulum, Mitochondria, Lysosomes, Golgi Apparatus
This is A thin, elastic structure (7.5-10 nm thick) enveloping the cell.
CELL MEMBRANE
This is Also called plasma membrane.
CELL MEMBRANE
CELL MEMBRANE COMPONENTS:
55%: ______
25%: ______
13%: ______
4%: ______
3%: ______
proteins
phospholipids
cholesterol
other lipids
carbohydrates
This is a Thin, double-layered film of lipids, one molecule thick.
LIPID BILAYER
______
- Most abundant lipids; Composed of ______ (water-soluble) phosphate end and a ______ (fat-soluble) fatty acid end.
PHOSPHOLIPIDS, hydrophilic, hydrophobic
CELL MEMBRANE
______ PORTION
- ______ (fatty acid) tails attract each other, forming the membrane’s interior.
HYDROPHOBIC, Hydrophobic
CELL MEMBRANE
______ PORTION
- ______ (phosphate) heads interact with intracellular water on inside and extracellular water on outside.
HYDROPHILIC, Hydrophilic
PERMEABILITY OF LIPID LAYER IN MIDDLE OF MEMBRANE
Impermeable to ______ substances (e.g., ______, ______, ______).
water-soluble, ions, glucose, urea
PERMEABILITY OF LIPID LAYER IN MIDDLE OF MEMBRANE
Permeable to ______ substances (e.g., ______, ______, ______).
fat-soluble, oxygen, carbon dioxide, alcohol
CELL MEMBRANE
______ molecules are lipids in nature due to their fat-soluble steroid nuclei. They are dissolved in the bilayer of the membrane.
Cholesterol
CELL MEMBRANE
______ helps determine the permeability of the bilayer to water-soluble substances.
Cholesterol
CELL MEMBRANE
They Control much of the membrane’s fluidity.
Cholesterol
The Protein (Glycoprotein) Component of the Cell Membrane
TWO TYPES:
Integral Proteins
Peripheral Proteins
The Protein (Glycoprotein) Component of the Cell Membrane
TWO TYPES:
______ Proteins - Protrude all the way through the membrane.
Integral
The Protein (Glycoprotein) Component of the Cell Membrane
TWO TYPES:
______ Proteins - Attached to one surface of the membrane and do not penetrate all the way through
Peripheral
______ PROTEIN FUNCTION
- Allow water molecules and water-soluble substances (e.g., ions) to diffuse.
INTEGRAL
______ PROTEIN FUNCTION
- Transport substances across the membrane, including active transport against gradients.
INTEGRAL
______ PROTEIN FUNCTION
- Bind with water-soluble chemicals (e.g., peptide hormones) to relay signals to the cell interior.
INTEGRAL
______ PROTEIN FUNCTION
- Facilitate chemical reactions on the cell membrane.
INTEGRAL
______ PROTEIN FUNCTION
- Act as enzymes.
PERIPHERAL
______ PROTEIN FUNCTION
- Regulate transport through cell membrane pores.
PERIPHERAL
______
- The loose carbohydrate coat on the outside surface of the cell.
GLYCOCALYX
FUNCTION OF ______
- Negative charge repels negatively charged objects.
GLYCOCALYX
FUNCTION OF ______
- Cells to cell attachment
GLYCOCALYX
FUNCTION OF ______
- Receptors
GLYCOCALYX
FUNCTION OF ______
- Immune Reactions
GLYCOCALYX
FUNCTIONS OF GLYCOCALYX:
- Negative charge repels negatively charged objects
- cells to cells attachment
- receptors
- immune reactions
This is a network of tubular structures (cisternae) and vesicles in the cytoplasm.
ENDOPLASMIC RETICULUM
This processes and transports molecules to cell destinations.
ENDOPLASMIC RETICULUM
This is up to 30-40 times the cell membrane area in some cells.
ENDOPLASMIC RETICULUM
Their walls are lipid bilayer membranes with large amount of proteins.
ENDOPLASMIC RETICULUM
______ space connects with the nuclear membrane space.
ENDOPLASMIC RETICULUM
______ directs substances to other cell parts and supports metabolic functions.
ENDOPLASMIC RETICULUM
______ attached to the outer surfaces of many parts of the ER. Where these particles are present, the reticulum is called the ______ (______) endoplasmic reticulum.
Ribosomes, rough, granular
______ composed of RNA and proteins.
Ribosomes
This lacks attached ribosomes (agranular ER).
SMOOTH ENDOPLASMIC RETICULUM
This Synthesizes lipid substances for other cellular processes promoted by intrareticular enzymes.
SMOOTH ENDOPLASMIC RETICULUM
This is Closely related to ER.
GOLGI APPARATUS
Small transport vesicles (also called endoplasmic reticulum vesicles (ER vesicles)) continually pinch off from the ER and shortly thereafter fuse with the _______
Golgi apparatus
Substances entrapped in ER vesicles are transported from the ER to the ______
Golgi apparatus
Substances entrapped in ER vesicles are transported from the ER to the ______
Golgi apparatus
Transported substances are processed in ______ to form lysosomes, secretory vesicles, and other cytoplasmic components
Golgi
These are Vesicular organelles that form by breaking off from the Golgi apparatus; they then disperse throughout the cytoplasm.
LYSOSOMES
LYSOSOMES Provide an intracellular digestive system that allows cell to digest:
(1) damaged cellular structures
(2) food particles that have been ingested by the cell
(3) unwanted matter such as bacteria.
One of their important functions: secretion of special chemical substances.
SECRETORY VESICLES
These are Formed by the ER-Golgi apparatus system
SECRETORY VESICLES
SECRETORY VESICLES are Released from the Golgi apparatus into the cytoplasm as ______.
storage vesicles
These are the Powerhouses of the cell
MITOCHONDRIA
These are Present in all areas of each cell’s cytoplasm, total number per cell varies from < 100 up to several thousand, depending on the energy requirements of the cell.
MITOCHONDRIA
This is the Control center of cell
NUCLEUS
This Sends messages to cell to grow and mature, replicate, or die.
NUCLEUS
This Contains large quantities of DNA
NUCLEUS
This is also called nuclear envelope
NUCLEAR MEMBRANE
This is Two separate bilayer membranes
Outer membrane continuous with ER, cytoplasm
NUCLEAR MEMBRANE
Space between 2 nuclear membranes is continuous with the space inside the ______
ER
This is the Maintenance of nearly constant conditions in the internal environment.
HOMEOSTASIS
______ - a state of disrupted homeostasis
Disease
______ MECHANISMS
- Continue to operate and maintain vital functions through multiple compensations
HOMEOSTATIC
BP can damage various organs, including the kidneys, causing even greater increases in ______ and more ______.
blood pressure, renal damage
HOMEOSTATIC MECHANISMS
Represent trade-offs that are necessary to maintain vital body functions but, in the long term,
contribute to additional ______ of body function.
abnormalities
Most control systems of the body act by ______.
negative feedback
NEGATIVE FEEDBACK
REGULATION OF CARBON DIOXIDE CONCENTRATION
a.) High concentration of CO2 in the extracellular fluid increases ______
b.) This, in turn, ______ extracellular fluid CO2 concentration.
c.) High concentration of CO2 initiates events that decrease the concentration toward normal, which is ______ to the initiating stimulus.
d.) Conversely, a CO2 concentration that falls too low results in feedback to increase the concentration. This response is also ______ to the initiating stimulus
pulmonary ventilation, decreases, negative, negative
NEGATIVE FEEDBACK
ARTERIAL PRESSURE-REGULATING MECHANISMS
- High pressure causes reactions that ______ pressure
- Low pressure causes reactions that ______ pressure
- These effects are ______ with respect to the initiating stimulus.
- If a factor becomes excessive or deficient, a control system initiates ______, consisting of changes that return the factor toward a mean value, maintaining ______.
reduce, increase, negative, negative feedback, homeostasis
POSITIVE FEEDBACK
“______ Cycles,” initiating stimulus causes more of the same
Vicious
Body sometimes uses ______ feedback to its advantage
positive
POSITIVE FEEDBACK
Example no. 1: ______
- Activation: When a blood vessel ruptures, multiple enzymes called clotting factors are activated within the clot.
- Chain Reaction: These enzymes activate adjacent inactive enzymes, leading to more clotting.
- Completion: The process continues until the vessel hole is plugged and bleeding stops.
BLOOD CLOTTING
POSITIVE FEEDBACK
Example no.2: ______
- Stretching of the cervix sends signals to the uterus, causing stronger contractions
CHILDBIRTH
POSITIVE FEEDBACK
GENERATION OF NERVE SIGNALS
- Stimulation of nerve fiber causes slight ______ leakage through channels.
- ______ entry changes membrane potential, opening more channels, potential, more change of potential, still more opening of channels, and so forth.
- Slight leak becomes an explosion of sodium entering the interior of the nerve fiber, which creates the ______.
- ______ causes electrical current to flow along the outside and inside of the fiber, initiating additional action potentials until the signal reaches the end of the fiber
sodium, Sodium ions, nerve action potential, Action potential
Body is made up of cells organized into different functional structures (______) which contribute its share to the maintenance of homeostasis in the ______ (internal environment)
organs, extracellular fluid
When normal conditions are maintained in the ______ environment, the cells of the body continue to live and function properly
internal
______ are ways of the body to help regulate biochemical pathways to maintain the normal functioning of the different organs
Feedback mechanisms
