Ch.1 Continued Flashcards
Cell functions include:
- movement of substances across the cell membrane
- cell division to make new cells
- protein synthesis
Movement of substances from a region of high concentration to a region of low concentration. Can also occur across a membrane
Diffusion
Oxygen and carbon dioxide can diffuse through cell membranes. Diffusion can occur across a membrane as long as the membrane is permeable to the substance involved.
Oxygen and carbon dioxide are able to diffuse through the cell membrane. When Carbon dioxide builds up in the capillaries to concentration that is higher in the lungs, the CO2 diffuses where to be exhaled?
Similarly, when the level of oxygen in the capillaries is lower than the oxygen in the lungs, oxygen diffuses into where for distribution into the body cells?
So, this way, the gases are exchanged between the air and the blood in the lungs, and between the blood and cells of the various tissues.
- The CO2 diffuses into the lungs to be exhaled
- Oxygen diffuses into the capillaries for it to b distributed through the body cells
Diffusion of water from a selectively permeable membrane. Movement from low solute concentration to a region of high solute concentration.
Osmosis
Molecular movement down a concentration gradient
simple diffusion
When red blood cells (RBC’s) are placed in the following (isotonic, hypertonic, and hypotonic) solutions what will happen?
Isotonic: RBC’s will stay the same
Hypertonic: water will leave the RBC’s and enter the surrounding fluid in the environment causing the cell to shrink or crenate
Hypotonic: water will enter the RBC’s making the cell swell and even possibly rupture (called hemolysis)
If a red blood cell, which contains 5% glucose, is placed in a container of 5% glucose solution, how will water move in both directions at the same rate because?
The glucose concentration inside and outside the cell are the same (isotonic)
When a red blood cell is placed in a 10% glucose solution, water will leave the cell (where there are more water molecules) and enter the surrounding fluid (where there are fewer water molecules). When fluid leaves the cells, they will what?
P.S. The 10% glucose solution has a greater solute concentration than the cell.
The cells will shrink (hypertonic)
When a red blood cell is placed in distilled water (that has a low solute concentration than the cell), water will enter or exit the cell when there are more water molecules outside the cell than the inside?
enter the cell making it a hypotonic solution
As water enters the cell, it will swell because of the increased volume. If enough water goes into the cell making it rupture it is known as what?
When this happens specifically to a red blood cell it is called?
lysis… to a red blood cell–> hemolysis
Pressure pushes the particles through a membrane. Movement of solvent using hydrostatic pressure; requires membrane filter.
Filtration
What is this an example of?
Blood is filtered through membranes in the kidney as the initial step of urine formation.
Filtration
What happens when blood is filtered through membranes in the kidney as the initial step of urine formation? (2)
-water and small molecules pass through filtration membrane
- blood cells remain in the blood
Process that moves substances across or through a membrane and does not require cellular energy.
What is this and what are the 3 things involved in this?
Passive transport:
- Simple diffusion
- Osmosis
- Filtration
Maintains concentration gradients. Moves molecules “uphill” from an area of low concentration to high concentration. Cellular energy is required in the form of ATP. Uses carrier molecules. If ATP is not available, this ceases immediately. Some substances are presented in significantly higher concentrations on one side of the membrane than on the other.
Active transport
This is an example of what?
Sodium ions more concentrated inside or outside the plasm membrane? Potassium ions concentration is higher inside or outside the cell?
Active transport:
sodium ions: outside
potassium ions: inside
Active transport is also used to transport amino acids and glucose from what organ into the blood?
small intestine
Formation of vesicles to transfer particles and droplets from outside to inside the cell. Material is too large to enter the cell by diffusion or active transport. Requires ATP energy.
Endocytosis
Endocytosis has two types:
phagocytosis and pinocytosis
white blood cells that engulf and destroy bacteria
phagocytes
“cell eating”. Cell membrane engulfs a particle to form a vesicle in the cytoplasm. Lysosomes fuse with the vesicle and the enzymes digest the particle
phagocytosis
“cell drinking”. important in cells that function in absorption.
pinocytosis
Difference between pinocytosis from phagocytosis:
- vesicles that are formed are much smaller and their contents are fluid
Secretory products are packaged into vesicles by the Golgi apparatus and released from the cell. The secretory vesicle moves to the cell membrane, where the vesicle membrane fuses with the cell membrane, and the contents are discharged to the outside of the cell.
Exocytosis
What are 2 examples of exocytosis?
- secretion of digestive enzymes from the pancreas
- secretion of milk from mammary glands
The process by which new cells ae formed for growth, repair, and replacement in the body.
Cell Division
More than 2 million of what are worn out and replaced every second of every day?
red blood cells
What cells are continually sloughed off the body’s surface and must be replaced?
skin cells
What lining is replaced every few days?
lining of the stomach
Somatic cells divide to form two new “daughter cells”, each identical to the parent cell.
Mitosis
Humans have how many pairs of chromosomes? How many total chromosomes?
23 pairs, 46 in total
What are the stages of mitosis?
1.) Interphase
2.) Prophase
3.) Metaphase
4.) Anaphase
5.) Telophase
period between active cell divisions
Interphase
chromatin shortens to form chromosomes
Prophase
chromosomes align along the center of the cell
Metaphase
chromosomes migrate to opposite ends of the cell
Anaphase
Cell divides to begin to form two daughter cells that are exact copies of the parent cell
Telophase
Division of the cell at the end of mitosis to form two separate daughter cells.
Cytokinesis
Only occur in reproductive cells (gametes)–eggs or sperm. Gametes only have 23 chromosomes. When fertilization takes place: resulting cell will have 46 chromosomes= 23 from egg and 23 from sperm
Meiosis
DNA in the nucleus directs the synthesis of the protein in the cytoplasm to determine: (2)
- Determine the structural and functional characteristics of an individual
- The purpose of DNA replication is to produce genes in the offspring that are exactly the same as those in the parents.
Portion of a DNA molecule that contains the genetic information for making on particular protein molecule.
Gene
Microscopic study of tissues
Histology
Nonliving material that fills the space between cells. Contains salts and fibers that are unique to a specific tissue and give the tissue distinctive characteristics
Intercellular matrix
Where is epithelial tissue located?
- all body surfaces
- line body cavities and hollow organs
- major tissue in glands
Function of Epithelial Tissue:
- protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception
Is avascular (without blood vessels) so they must receive nutrients and oxygen supply by diffusion. They regenerate and reproduce quickly
Epithelial tissue
flat and nuclei are usually broad and thin
squamous cells
cubelike, as tall as they are wide, and nuclei are spherical and centrally located
cuboidal cells
cells are tall and narrow, resembling columns and nuclei are usually in the lower part of the cell near the basement membrane
columnar cells
attaches epithelial tissue to underlying connective tissue
basement membrane
have only 1 layer of cells
simple
have multiple layers
stratified
Consists of a single layer of thin, flat cells that fit closely together with little intercellular matrix. Because it’s so thin, it is well suited for areas in which diffusion and filtration take place.
simple squamous epithelium
Where is the simple squamous epithelium found in?
- alveoli of the lungs
- kidney, where blood is filtered
- capillary walls
True or False?
Capillary walls are made up of simple squamous epithelium.
True
Consists of a single layer of cube-shaped cells. These cells have more volume than squamous cells and also have more organelles.
Simple cuboidal epithelium