Chapter 2: The Cell and Its Function Flashcards
2 major parts of the cell
Nucleus and Cytoplasm
What structure separates the nucleus from the cytoplasm?
Nuclear membrane
What structure separates the cytoplasm of the cell from the surrounding fluids?
cell membrane or plasma membrane
The different substances that make up the cell is called the:
protoplasm
5 basic substances that compose the protoplasm:
Water Electrolytes Proteins Lipids Carbohydrates
According to Guyton, most cells are comprised mainly of water. With the EXCEPTION of ______ cells
Fat cells (adipocytes)
**In fat cells (adipocytes), triglycerides often account for as much as 95% of the cell mass.
Average water concentration of the cell:
70-85%
Which of the following ions is found only in smaller quantities in the cell? A. Bicarbonate B. Calcium C. Phosphate D. Magnesium
B. Calcium
Important ions in the cell include potassium, magnesium,
phosphate, sulfate, bicarbonate, and smaller quantities
of sodium, chloride, and calcium.
After water, the most abundant substances in the cells are:
Proteins
Proteins constitute what percentage of the cell mass?
10-20%
Which type of proteins present in the cell are mainly in the form of long filaments that are polymers of many individual protein molecules?
Structural proteins
The other type is the functional protein
What structure provides the cytoskeletons of cellular organelles such as cilia, nerve axons, mitotic spindles, and tangled mass of thin filamentous tubules that that hold the parts of the cytoplasm and nucleoplasm together in their respective compartments?
Microtubules
These structural proteins are found outside the cell, especially in the collagen and elastin fibers of connective tissue, and elsewhere, such as in blood vessel walls, tendons, and ligaments.
Fibrillar proteins
- *Microtubules - structural proteins inside
- *Fibrillar proteins - structural proteins outside
These types of proteins are mainly the enzymes of the cell and, in contrast to the fibrillar proteins, are often mobile in the cell fluid.
Functional proteins
Which type of cellular protein is adherent to membranous structures inside the cell and catalyzes specific intracellular chemical reactions?
Functional proteins
**These proteins are mainly the enzymes of the cell and, in
contrast to the fibrillar proteins, are often mobile in the
cell fluid.
Phospholipids and cholesterol together constitute __% of the total cell mass?
2%
Phospholipids and cholesterol are mainly insoluble in water and therefore are used to form the cell membrane and intracellular
membrane barriers that separate the different cell compartments.
Lipid component of the cell that is known as “neutral fat”
Triglyceride
These cells store the body’s main storehouse of energy-giving nutrients that can later be used to provide energy wherever it is needed in the body.
Adipocytes
**In fat cells (adipocytes), triglycerides often account for as much as 95% of the cell mass. The fat stored in these cells represents the body’s main storehouse of energy-giving nutrients that can later be used to provide energy wherever it is needed in the body.
What is the maximum amount of carbohydrates stored in muscle and liver cells? (percentage)
3% in muscle cells and 6% in liver cells
**Most human cells do not maintain large stores of carbohydrates; the amount usually averages only about 1% of their total mass but increases to as much as 3% in muscle cells and, occasionally, to 6% in liver cells.
This is the insoluble polymer of glucose that can be depolymerized and used rapidly to supply the cell’s energy needs
Glycogen
**carbohydrate in the form of dissolved glucose is always present in the surrounding extracellular fluid so that it is readily available to the cell. Also, a small amount of carbohydrate is stored in cells as glycogen, an insoluble polymer of glucose that can be depolymerized and used rapidly to supply the cell’s energy needs.
The loss of which organelle will result to immediate cessation of 95% of the cell’s energy release from nutrients?
Mitochondria
In membranes of organelles, protein molecules often penetrate all the way through membranes, thus providing specialized pathways, often organized into actual ______, for passage of specific substances through membranes
Pores
The approximate percent composition of the cell membrane as to proteins:
55%
55% proteins 25% phospholipids 13% cholesterol 4% other lipids 3% carbohydrates
The approximate percent composition of the cell membrane as to phospholipids:
25%
55% proteins 25% phospholipids 13% cholesterol 4% other lipids 3% carbohydrates