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What is something that is always happening at every moment? It is a physical and chemical events that release or use energy.
Requirements of the organisms that are essential to the maintenance of life?
- pressure (blood/atmospheric)
Maintenance of a stable internal environment is
What do homeostatic mechanisms regulate? (Always trying to find balance...)
- blood pressure
- body temperature
- blood glucose
- respiratory rate
What are the majority of homeostatic mechanisms controlled through?
What is negative feedback?
- The body's way of getting back into balance.
- "Seeks to cancel the output that has caused it, this is known as a self-correcting loop"
- Ex: temp. in the room (external environment) is too warm, the body will take this infomation as negative and it will regulate the body (using both voluntary and involuntary actions) until it gets back to 98.6°
Approximately how many cells make up the human body?
What is a hypothetical cell that includes many known cell structures?
What are the three major parts to a cell?
- Cell membrane
- Cell nucleus
What are the key characteristics of a cell membrane?
- thin & flexible (able to bend & contour to our shape)
- composed MAINLY of lipids (fats)
- phospholipid bilayer
- some proteins
- selectively permeable
- signal transduction
- intercellular junction
- membrane proteins
- O2, CO2, & lipids pass easily through cell membrane
- aa, water, proteins, sugars, various ions do not pass through membrane as easily
What is signal transduction?
- receive and respond to incoming messages (get bigger/get smaller)
- a signalling molecule activates a certain receptor on the cell membrane
- causing a second messenger to continue the signal into the cell and elicit a physiological response.
What are connections between cell membranes (i.e. skin cells) called?
What are the intercellular junctions?
- Tight junction (like a belt tightened around two ends of a cell)
- Domesomes (like a spot weld, holding on tight)
- Gap junction (tunnel connector from cell to cell - passes nutrients)
What are membrane proteins?
- Cell surface proteins
- Cell adhesions molecules (CAMs)
- Proteins that guide certain cells to a specific area
- WBC guided to area of infection
- Help cells bind to each other
What are the key characteristics to Cytoplasm?
- Contains organelles "workers"
- -endoplasmic reticulum (ER)
- -golgi apparatus
- -microfilaments & microtubules
Which of the organelles is the communication & transport system within the cell? It also participates in protein & lipid synthesis.
"Rough" orgnaells, tiny spherical structures that are composed of protein. (not part of the membrane)
The Fed-Ex of the organells. Flattened, membranous sacs that refine, package and deliveres proteins synthesized on the rough ER.
An organell that is shaped like enlongated fluid filled sacks, synthesizes the ATP (adenosine triphosphate) for the cell, known as the "powerhouse" of the cell because it creates energy for the cell to use. A typical cell has about 1700 of them, but cells with higher energy requirements have many thousand in them.
An organell that is know as the "garbage dispoals" of the cell, where enzymes dismantle debris.
Organell that are membranous sacks that resemble lysosomes in shape and size. Most abundantly found in the liver and kidneys. They contain enzymes that break down hydrogen peroxide (which is a toxic waste to cells)
Organell known as the "central body" or "cell churro", plays an important role during cell division. It is located close to the nucleus and consists of two cylinders, or tube like structures or mirotubes, that lie at a right angle to eachother. During cell division they migrate to either side fo the nucleus...
Organell's that are membranous sacs that vary in size and contents. They may form when a portion fo the cell membrane folds inward and pinches off. As a result, a bubble like thing containing some liquid or solid formerly OUTSIDE the cell in INSIDE the cell or cytoplasm. (End of a neuron)
Two types of threadlike structures in the cell. One is composed of tiny rodsof the protein that typically form meshwork or bundles that provide certain cellular movements. (shortening/cntracting of cells). The other are long, slinder tubes with larger diamerters. They are composed of a globular protein, making them more ridigid so they help maintain the shape of the cell. (Like the rebar in concrete)
Microfilaments & microtubules
"Control tower" of the cell
A dense structure in the nucleus, largely composed of RNA and protein. Produces ribosomes.
Consists of loosley coiled fibers in the nuclear fluid. These fibers are composed of continuous DNA molecules wrapped around clusters fo proteins called histones, like beads in a string. They get more compacted during cell division and become rod like in structure. "Colored body" "Colored substance"
Cell extensions, cylindrical, hair like, fringe like, attaches just beneath the cell membrane to the basal body. Move in a to and fro manner, creating a wave - ex propelling muscus over the lining fo the respratory tract. Present in larghe #'s. Short.
Single (one per cell) , longer, (only found in sperm).
A barrier that controls which substances enter and leave a cell.
O2 and water IN
CO2 and waste OUT
What is a movement of molecules (not water) from an area of HIGH concentration to an area of LOW concentration.
Ex: Sugar cubes in water or food coloring in water
What uses energy and a carrier protein (bouncer at the club door) to move molecules from and area of high concintration to low consintration?
What is the diffusion of WATER molecules across a selectively permeable membrane?
When molecules are foced through a membrane (ex: making coffee or blood vessels)
When energy and carrier proteins are used to move molecules from an area of low concentration to an area of high concentration?
Molecules/particles that are too large to move through other methods, enter the cell through
Cell "drinking" - liquid
Cell "eating" (WBC) -solids
Molecules/particle that are too large to move through other methods, exit the cell throuhg...
A combination of endo/exocytosis, something enters the cell, changes, and then leaves.
The series of changes a cell undergoes form the time it forms until the time it reproduces
The cell cycle
Interesting, people, make, awesome, teachers
Duplication of cell contents (Prepping for reproduction), very active period, chromosomes (DNA) and organells
- Cell division, (includes the PMAT or IPMAT)
- New cells have 46 chromosomes
The phase of cell division where chromosomes appear and spindle fibers form on centrosomes
The phase of cell division where chromosomes align midway between centrioles and spindles attach to chromosomes
Phase of cell division where duplicated chromosomes separate
The final stage of cell division, 2 cells, chromosomes unwind and become chromatin
Name 4 of the 10 characteristics of life
Physical/chemical events that release energy, happening constantly
What is the term used to describe the maintenance of a stable internal environment?
How are most homestatic mechanisms/processes controlled?
What are the 3 major parts of a cell?
What is contained in the cytoplasm?
What is the name for the movement of water across a selectively/semi permeable membrane?
Osmosis (High to low water)
How do molecules move from an area of high concentration to low concentration?
What is the definition of active transport?
movement of molecules (with help of carrier proteins & energy) from an area of low concentration to high concentration
During cell division, what portion involves the most activity?
What is the term used to describe the expression of different genes within the cell, instructing that cell to become a certain type of cell?
What is the term used to describe movement of a molecule that is too large to enter through normal circumstances?
Endocytosis (in) or exocytosis (out)