Question | Answer |
Why is the selective permeability of the plasma membrane essential for normal cell function? | Selective permeability allows cells to exclude some substances and allow others to pass into or out of the cell. |
What is the primary energy-transferring compound of the body? | ATP |
What are the 3 main parts of a human cell? | Plasma membrane, cytoplasm, and nucleus. |
In what order do elements interact in a homeostatic control system? | The receptor, the control center and the effector. |
What is true of negative feedback mechanisms? | The output shuts off the original stimulus or reduces its intensity. |
What type of membrane junction is an example of a tight junction? | Junctions among epithelial cells lining the digestive tract. |
What is a membrane potential? | a voltage or electrical charge across the plasma membrane |
What factors act to bind cells together? | Specialized junctions, wavy membrane contours, and glycoproteins |
___________ is an adapter molecule which brings amino acids to the ribosome to build a protein. | t-RNA |
Why do cells need active transport mechanisms? | to move solutes against their concentration gradients |
What sort of Ca2+ concentrations are maintained by the calcium pump? | The Ca2+ concentration is higher in the extracellular fluid than in the cytoplasm. |
Most cancer cells have a lower intracellular ATP concentration compared to normal cells. How would you expect this to affect the Na+-K+ pump in cancer cells? | The Na+-K+ pump would work slower. |
What is the energy source used by the Na+-K+ pump during its normal operation? | hydrolysis of ATP |
What best describes how phosphorylation affects the Na+-K+ pump? | Phosphorylation causes the pump to change shape. |
What triggers the release of phosphate from the Na+-K+ pump? | binding of K+ ions to the pump |
What event initiates ATP attachment to the Na+-K+ pump, leading to the pump's phosphorylation? | the binding of Na+ ions to the pump |
What sort of ion distributions are established and maintained by Na+-K+ pump activity? | high Na+ concentration in the extracellular fluid; high K+ concentration in the cytoplasm |
What is a function of the rough endoplasmic reticulum? | synthesis of the cell's membranes |
Nonpolar molecules are the result of what? | unequal electron pair sharing |
What is the role of the serous membranes covering some organs? | to prevent friction between the organ and body cavity wall |
The PH scale is based on what? | the concentration of H+ ions. |
What helps to stabilize blood PH? | Buffers |
What is the classification of a solution with a pH of 8.3? | alkaline solution |
The dorsal body cavity is subdivided into what subdivisions? | The vertebral/spinal and cranial cavities. |
What demonstrates the principle of complementarity of structure and function? | Bones can support and protect body organs because they contain hard mineral deposits. |
What correctly describes the plasma membrane? | It is a dynamic fluid structure that is in constant flux. |
Is the knee proximal or distal to the thigh? | Distal |
What is a difference between primary and secondary active transport? | In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. |
What is the site of ribosome assembly in a cell? | The nucleolus |
Which specific body cavity houses the heart and lungs? | thoracic |
True or False
Oxygen Gas is a compound | False |
What defines covalent bonds? | The bond formed when shared electrons occupy a single orbital common to both atoms within a molecule. |
What is a difference between a compound and a mixture? | No chemical bonding occurs between the components of a mixture. The properties of atoms and molecules are not changed when they become part of a mixture. |
What is the regional term which includes the head: | The axial part |
Name a primary function of peroxisomes? | 1. They contain powerful enzymes called catalases.
2. To aid in the neutralization of dangerous free radicals.
3. They contain powerful enzymes called oxidases. |
The regulation of body temperature is an example of which type of homeostatic control? | Negative feedback |
An element has an atomic number of 17 and a mass of 35. How many protons, neutrons, and electrons does the element have? | 17 protons, 18 neutrons, and 17 electrons |
What is one example that would not diffuse through the plasma membrane by means of simple diffusion? | Glucose |
Which directional term is used to describe the relationship of the skin relative to the skeletal muscles? | superficial |
What is the proper description of the human body in the anatomical position? | The body is erect with feet slightly apart, and palms face forward with thumbs pointing away from the body. |
What is true regarding the pH of a solution? | The more hydrogen ions in a solution, the more acidic the solution is. |
True or False
The navel is caudal to the chin. | True |
Which four elements comprise approximately 96% of body weight? | Carbon, oxygen, hydrogen, and nitrogen. |
What must happen before a body cell can divide? | Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring. |
The hand is __________ to the shoulder. | distal |
Choose the correctly matched pair.
1. Nucleotide: DNA
2. Glycerol and fatty acids: RNA
3. Amino acid: carbohydrate
4. Monosaccharide: lipid | 1. Nucleotide: DNA |
In their resting state, all body cells exhibit a resting membrane potential; therefore, all cells are _______. | polarized |
Solutions with a higher concentration of solutes than the concentration inside the cell are: | hypertonic. |
Which organic molecules form the major structural materials of the body? | proteins |
What can be described as cuts made diagonally between the horizontal and the vertical planes? | Oblique sections |
What is true regarding the pH of a solution? | The more hydrogen ions in a solution, the more acidic the solution is. |
True or False
The navel is caudal to the chin. | True |
Which four elements comprise approximately 96% of body weight? | Carbon, oxygen, hydrogen, and nitrogen. |
What must happen before a body cell can divide? | Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring. |
The hand is __________ to the shoulder. | distal |
Choose the correctly matched pair.
1. Nucleotide: DNA
2. Glycerol and fatty acids: RNA
3. Amino acid: carbohydrate
4. Monosaccharide: lipid | 1. Nucleotide: DNA |
In their resting state, all body cells exhibit a resting membrane potential; therefore, all cells are _______. | polarized |
Solutions with a higher concentration of solutes than the concentration inside the cell are: | hypertonic. |
Which organic molecules form the major structural materials of the body? | proteins |
What can be described as cuts made diagonally between the horizontal and the vertical planes? | Oblique sections |
True or False
Some types of cells move freely through the body, while others are bound into tightly knit communities. | True |
What is one of the three basic steps involved in enzyme activity? | The enzyme's active site binds to the substrate(s) on which it acts, temporarily forming an enzyme-substrate complex. |
___________ is the diffusion of a solvent, such as water, across a selectively permeable membrane. | Osmosis |
Which body systems are absolutely essential for homeostasis? | nervous and endocrine systems |