Chapter 3 Flashcards
1
Q
- Describe the components of the plasma
membrane
A
- Plasma membranes are the skin of the cell
- It is semi permeable because it lets in some things are not others
- The membrane is made of phospholipids whose heads are attracted to water and tails are hydro-phobic scared of water.
o Heads are on the outside of the skin and the two tails touch on the inside - Components in the phospholipid membrane:
o Proteins – transport material across the membrane
o Carbohydrates – stick out from the cell on the outside, receptors
o Cholesterol – gives rigidity to membrane
2
Q
- Describe the structure and function of tight junctions, desmosomes, and gap junctions.
A
- Junctions connect two cells together
o Tight junctions – zipper like water tight seal, ex. Bladder needs to be water tight
o Desmosomes – rivets between 2 cells that allow flow between them ex. Skin, intentines
o Gap – tunnel between 2 cells that allows passing of substances between them
3
Q
What is the nucleus?
A
- Nucleus – headquarters or control center of the cell
o Its function is to build proteins to make the human body using the DNA and genes it has
4
Q
- Describe the structure and function of the cytoplasm
A
- Cytoplasm is the gel inside the cell
- Giving the cell its shape, helps material pass from one organelle to another
5
Q
- Describe the structure and functions of each cytoplasmic organelle.
A
- Mitochondria – break down food releasing energy (ATP molecules) which powerhouse the cell
- Ribosomes – chefs making proteins
- Endoplasmic Reticulum (ER) - (super highway of a cell) transport vehicles with membrane tunnels that are circulatory system of a cell, carrying proteins around the cell (can be rough or smooth)
- Golgi apparatus – (traffic director of proteins) modifying, packaging, and shipping proteins
- Lysosomes – (Garbagemen of unusable cell content) cellular stomachs digesting cell debris and unusable cell structures
- Peroxisomes – (policemen) disarm dangerous substances like alcohol or poisonous substances
- Centrioles – used during cell division, rod shaped
6
Q
- Explain the difference between passive and active transport across the plasma membrane.
A
- Passive transport – When things just pass through the membrane
- Active transport – cell uses energy (ATP) to cross through the membrane
7
Q
What is diffusion, simple diffusion and facilitated diffusion
A
- Diffusion - following the concentration gradient
- Simple diffusion – molecule passes through membrane unassisted
- Facilitated (helped) diffusion – molecule is assisted passing through the membrane by proteins
o The membrane changes the molecule chemically
8
Q
- Define the process of osmosis
A
- Osmosis - water through a membrane
- Water is a gold digger and follows solutes wherever there are more
9
Q
- Define tonicity and describe how it relates to osmosis.
A
- Tonicity - Solution changing the size of the cells water content
- Hypotonic = more water, less solutes hippos love water, inflated the cell
o this low concentration of solutes will be attracted to inside the cell (good for dehydrated people) - Hypertonic solution – more solutes in the solution, than inside the cell, deflates cell
o Given to patients who have swelling in their cells due to water retention - Isotonic solution - no changes in Cells, have the same water and solute concentration as cells do
10
Q
- Define osmotic pressure and explain how it relates to fluid movement across the plasma membrane.
A
- Osmotic pressure – when the pressure stops the water from going in the cell
the more solutes in the water give it more pressure and the exact pressure where the flow of water stops is the osmotic pressure
o Higher concentration of solutes attract more water, and a higher pressure would be needed to stop the water flow from coming in
11
Q
What is filtration and how does it move things across the plasma membrane?
What is a pressure gradient?
A
Filtration - pressure push things through the membrane
o A pressure gradient pushs high pressure solutes through a filter into a low pressure area against its concentration gradient
12
Q
- Define exocytosis and endocytosis
A
- Exocytosis – exits things out of cell such as hormones or mucus
- Endocytosis – take things into the cell
Both use ATP (energy) in the membrane
13
Q
- Describe the impact of aging on the cell
A
Slow healing
Less cell division
Less energy being made
14
Q
- Review the definition of a tissue
A
- Tissue – groups of cells that are similar in function and structure
15
Q
- List the four major tissue types and their chief subcategories
A
Muscle – movement
Epithelial - covering
Nervous - control
Connective - support
16
Q
What are epithelial tissues?
A
- Covers and lines all free body surfaces, it protects the body, absorbs, filters, and secretes. It protects from the outside of skin to absorbing inside the digestive system
- Form continuous sheets in one or many layers
