Test #1: Cell & Connective Tissue Flashcards
What is a Cell?
The cell is the basic structural and functional unit of living organisms.
What are cells bathed in?
Cells are bathed in a diluted saltwater solution called interstitial fluid.
How much do cells vary in their structure and function?
Cells vary greatly in their structure and function.
How many cells compose the human body?
The human body is composed of trillions of cells.
What is interstitial fluid?
a .It is the fluid which exists between the cells.
b. It’s a nutrient rich soup.
c. It’s a byproduct of blood.
d. Cells get their nutrients, hormones and electrolytes from interstitial fluid.
e. Also gets rids of their waste into this fluid.
How many basic parts make up generalized animal cells?
3 basic parts
What are the 3 basic parts that make up generalized animal cells?
- Nucleus; 2. Plasma Membrane; and 3. Cytoplasm
What is the Nucleus?
a. Centrally located within the cell.
b. Control center or “brains” of the cell.
c. One or many within the cell.
d. Generally takes on the shape of the cell.
e. It is where DNA (our genetic blueprint) is located.
What is the Plasma Membrane?
The outer border or boundary of a cell.
What is the Plasma Membrane made up of?
It is made up of fat, protein, cholesterol and sugar.
How many parts make up the main structure of the Plasma Membrane?
2 parts
What are the 2 parts that make up the main structure of the Plasma Membrane?
- Lipids (fats); and 2. Proteins
Plasma Membrane: Lipids (Fats)
a. Are arranged in a double layer (heads with tails): o-|-o
b. Heads are hydrophilic: o
c. Tails are hydrophobic: -
What is hydrophilic?
“Water loving” – Can interact with water
What is hydrophobic?
“Water hating” – Repels water
Plasma Membrane: Proteins
a. Are scattered throughout the plasma membrane.
b. They act as receptor sites.
c. Also act as passageways.
How many functions of the Plasma Membrane?
3 functions
What are the 3 functions of the Plasma Membrane?
- Membrane transport; 2. Maintenance of an electrical gradient; and 3. Interaction with the outside environment
Plasma Membrane: Membrane Transport
a. The plasma membrane is selectively permeable, choosing what can enter/exit the cell.
b. This membrane transport can be either active or passive.
Passive Plasma Membrane Transport: Is energy required?
No energy is required.
How many methods of passive membrane transport?
2 methods
What are the 2 methods of passive membrane transport?
- Diffusion; and 2. Osmosis
Passive Plasma Membrane Transport: Diffusion
a. Molecules move from an area of high concentration to low concentration.
b. Molecules move “down hill”.
Passive Plasma Membrane Transport: Osmosis
a. Movement of water from an area of high concentration to low concentration.
b. Water always follows salts and proteins.
Active Plasma Membrane Transport: Is energy required?
Energy is required.
How many methods of active membrane transport?
2 methods
What are the 2 methods of active membrane transport?
- Endocytosis; and 2. Exocytosis
Active Plasma Membrane Transport: Endocytosis
Cell is bringing material (within) inside.
How many specific forms of endocytosis?
2 specific forms
What are the 2 specific forms of endocytosis?
- Pinocytosis; and 2. Phagocytosis
Endocytosis: Pinocytosis
“Cell drinking” - Bringing in a liquid
Endocytosis: Phagocytosis
“Cell eating” - Bringing in a solid
Active Plasma Membrane Transport: Exocytosis
Cell is getting rid of something (waste or proteins)
Plasma Membrane: Maintenance of an electrical gradient*
a. A plasma membrane maintains a separation of charges on either side of the membrane.
b. Positive on the outside; negative on the inside: -|+
c. This gives the cell the ability to conduct electricity.
d. It just needs to be stimulated to do so.
What chemical element is on the outside of the membrane to give it a positive charge?*
Sodium or Na+
Sodium (Na+) is “more positive” than Potassium (K+): K+|Na+ (-|+)
What chemical element is on the inside of the membrane to give it a negative charge?*
Potassium or K+
Potassium (K+) is “less positive” than Sodium (Na+): K+|Na+ (-|+)
Plasma Membrane: Interaction with the outside environment
Proteins and sugar molecules allow the plasma membrane to interact with material outside of the cell.
What is Cytoplasm?
Everything inside the plasma membrane and outside the nucleus.
How many components of Cytoplasm?
3 components
What are the 3 components of Cytoplasm?
- Cytosol; 2. Inclusions; and 3. Organelles
Cytoplasm: Cytosol
a. The watery portion.
b. Made up mostly of H2O with salts, proteins, hormones, organelles and waste floating in it.
Cytoplasm: Inclusions
Are chemicals floating in the cytoplasm that pertain to the function of that particular cell.
Examples:
melanin - pigment in skin cells
glycogen - a stored form of glucose in muscle cells
fat - in adipose cells
Cytoplasm: Organelles
The metabolic machinery of the cell.
Organelles: Ribosomes*
a. The site of protein synthesis.
b. Some float freely within the cytoplasm making protein for the cell, and
c. some are attached to membranes making protein for export to other regions of the body.
Organelles: Mitochondria*
a. The “power plant” of the cell providing it with energy in the form of ATP (from glucose).
b. The more productive the cell, the more mitochondria.
c. Muscle cells have many.
Organelles: Endoplasmic Retinaculum
a. A network of fluid filled tubes and membranes within the cytoplasm serving as anchor points for some ribosomes.
b. They also deliver proteins from one area of the cell to another.
c. Rough ER has ribosomes; Smooth ER does not.