Statements about cells:
> all cells have cell walls and internal structures that move
Light microscopes:
use light and glass lenses to magnify an image
One centimeter
10 millimeters
Resolution is
the ability to distinguish between to nearby objects as separate
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?
a light microscope, because it allows observation of whole live cells
The idea that all living things are composed of cells and that all cells come from other cells
cell theory
A scientist wants to magnify a pollen grain 8000 times and examine the ridges and pores on its surface. Which of the following instruments would be best?
a scanning electron microscope
A scanning electron microscope is used to study ______, where as a transmission electron microscope is used to study ______
cell surfaces ...... internal cell structures
The diameter of most animal cells and plant cells range from
10-100 micrometers
As cell size increases, the...
volume increases faster than the surface area
Which cell has the greatest surface-to-volume ratio?
bacterium
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation will become what?
will eventually be problematic since the cells ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasm needs
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?
Keep the cough drop whole. This maintains the largest surface-to-volume ratio and slows the dissolution of the cough drop
A pathologist who wants to examine a patient's liver cells to determine if the mitochondria have an internal structural defect will likely need to use a what kind of microscope?
transmission electron microscope
Many physiological conditions are related to particular proteins in cell membranes. The number of insulin receptors in membranes is related to the amount of insulin present around those cells. If the presence of increased insulin results in a decrease in receptors and a decrease in insulin results in an increase in an increase in insulin receptors, this would be an example of?
negative or regulatory feedback
The fluid mosaic model describes the plasma membrane as consisting of?
individual proteins and phospholipids that can drift in a phospholipid bilayer
Membrane phospholipids are able to do what in the plasma membrane?
often have "kinks" in their tails caused by the presence of a double bond between carbons
The cholesterol associated with animal cell membrane help solidify what?
helps to stabilize the cell membrane and body temperature
If you were working for a pharmaceutical company as part of a drug discovery team, which of these enzymes inhibitors would you suggest as a productive avenue for drug development?
a drug to treat high blood pressure that reversibly inhibits an enzyme catalyzing production of a chemical that causes blood vessels to contract
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID) inhibit inflammation by inhibiting an enzyme in the prostaglandin pathway, but by inhibiting this enzyme and this pathway they also inhibit pathways that protect the stomach from damage by stomach acid and that prevent aggregation of blood platelets to form blood clots. What can you conclude from this?
the enzyme is found in many different types of cells
Most of the functions of a cell membrane, including transport and enzymatic function, are performed by?
proteins
Statements regarding membrane protein function / transfer genetic information:
> serve as enzymes> act as receptors> provide cellular identification> form functions between cells
Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell occurs when?
a signaling molecule binds to a protein that extends to the outside of the cell (signal transduction)
Plasma membranes are selectively permeable. This means that the plasma membrane...
allows some substances to enter and leave a cell more easily than others
Statements regarding membrane function:
> forms a selective barrier> plays a role in signal transduction> has receptors for chemical messages> involved in self-recognition
Which characteristic promoted the utilization of lipids as the first cell membrane?
self-assembly into a simple membrane
All cells are enclosed by a plasma membrane that is similar in ________ and ________.
structure ..... function
Small, nonpolar, hydrophobic molecules such as fatty acids
easily pass through a membrane's lipid bilayer
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
Na+
Statements regarding photosynthesis and cellular respiration:
photosynthesis occurs in chloroplasts, and cellular respiration occurs in the mitochondria
How do cells capture the energy released by cellular respiration?
they produce ATP
The processes of photosynthesis and cellular respiration are complementary . During these conversions, some energy is...?
lost in the form of heat
Respiration ______, and cellular respiration ______
is gas exchange ...... produces ATP
Products of cellular respiration, like energy, make ______ and ______
energy to make ATP ...... carbon dioxide
Which of the following statements regarding cellular respiration is false?
cellular respiration is a single chemical reaction with just one step
The overall equation for the cellular respiration of glucose is...?
C6H12O6 + 6 O2 -----> 6 CO2 + 6 H2O + energy
Statements about the energy yields from cellular respiration like which are more efficient vs. gas used in care engine
cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from glucose
Humans use the calories they obtain from ______ as their source of energy
food
Humans use about ______ of their daily calories to maintain brain cells and power other life-sustaining activities
75%
A kilocalorie is defined as?
the quantity of heat needed to raise the temperature of 1 kg of water by 1 degree Celsius
The label on the box of breakfast cereal lists one serving as containing "200 calories" per serving. How many calories are actually in one serving?
200,000
During cellular respiration, the energy in glucose is carried by what?
electrons
During the redox reaction, electrons are...?
lost from one substance and added to another substance
Oxidation is the ______, and reduction is the ______
loss of electrons ...... gain of electrons
In biological systems, an important enzyme involved in the regulation of redox reactions is...?
dehydrogenase
During cellular respiration, NADH delivers its...?
electron load to the first electron carrier molecule
Which of the following statements regarding the movement of electrons during cellular respiration, oxygen is what when it accepts ...?
molecular oxygen is reduced when it accepts electrons and form water
The functioning of an electron transport chain is analogous to a slinky toy going down a flight of stairs
true
List the stages in cellular respiration in the correct order
glycolysis --> citric acid cycle --> oxidation phosphorylation
A drug is tested in the lab and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit the what cycle and what type of phosphorylation?
citric acid and oxidative phosphorylation
During which of the following phases of cellular respiration does substrate-level phosphorylation take place?
glycolysis and citric acid cycle
Which of the following metabolic pathways is common in aerobic and anaerobic metabolism?
glycolysis
As a result of glycolysis, there is a net gain of ______ ATP(s)
2
How many molecules of NADH are produced during glycolysis?
2