Ch. 3 The Cell Flashcards
____ are the basic structural and functional unit of life.
Cells
A cells _____ reveals its function.
Shape
The individual and collective activities of cells are necessary for ____ activity.
Organismal. Groups of cells such as muscle cells.
The biochemical activities of cells are dependent on their sub-cellular structures is known as
Principle of complementarity
Continuity of life is _____. Meaning what?
Cellular.
Cells can only arise from other cells
What are the three main parts of a human cell?
- Plasma membrane
- Cytoplasm
- Nucleus
This is the outer boundary of the cell which acts as a selectively permeable membrane.
Plasma membrane
What are functions of the plasma membrane?
- Separates the body’s major fluid components-extracellular and intercellular.
- Membrane transport
- Resting potential
What is the plasma membrane?
- Fluidic bilateral of phospholipids- 5% glycolipids 20% cholesterol
- Lipid rafts- stable regions
- Peripheral proteins- sit on the membrane
- Glycocalyx
What is the glycocalyx?
Carbohydrate rich covering of outer membrane containing glycolipids and glycoproteins
What are the 6 categories of proteins and the plasma membrane?
- Transport- carries through cell
- Receptors- detect chemicals from ECF
- Attachment- attach to either ECF or cytoplasmic fluid and other proteins. Help hold in place
- Enzymatic- needed to help catalyze
- Intercellular- holds proteins together.
What are 4 specializations of the plasma membrane?
- Microvilli
- Tight junctions
- Desmosomes
- Gap junctions
These are tiny fingerlike projections of the plasma membrane.
Microvilli
What is the purpose of microvilli?
To increase the surface area immensely in a small area without increasing the size of the cell.
Where are microvilli found?
Usually found in absorptive cells and inside the cytoskeleton.
This prevents molecules from passing through the intracellular space.
Tight junctions.
Right junctions are ____ to most larger molecules (but not some ions).
Impermeable
What are some examples of tight junctions?
Epithelial of digestive tract and the stomach- keeps acid inside
What are desmosomes?
They are anchoring junctions which reduce the chances of tissue tearing.
What is the function of desmosomes?
They help tissue resist mechanical strain especially those in constant motion.
Which tissues are desmosomes found in?
Skin and heart muscle (tissues under mechanical strain)
These provide direct communication between cells.
Gap junctions
These are small openings allowing ions, simple sugars and small molecules to freely diffuse.
Gap junctions.
What is the function of gap junction?
- Integral membrane proteins create a channel by passing plasma membrane.
- coordinating structure- if one thing happens to a cell it passes to the next cell-talk to each other.
This is how things get into and out of cells.
Membrane transport.
What are the 4 types of membrane transport?
- Diffusion
- Filtration
- Active transport
- Vesicular transport
Which membrane transports require no energy?
- Diffusion
2. Filtration
Which membrane transports require energy?
- Active transport
2. Vesicular transport
What are the 4 types of diffusion?
- Simple diffusion
- Facilitated diffusion
- Carriers
- Chanel’s - Osmosis
This is the tendency of molecules and ions to spread evenly throughout solution.
Diffusion