Midterm Biology

The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.

14. Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? A) Unsaturated fatty acids are more polar than saturated fatty acids. B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. C) The double bonds block interaction among the hydrophilic head groups of the lipids. D) The double bonds result in shorter fatty acid tails and thinner membranes. E) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.

They move laterally along the plane of the membrane

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids? A.) They move laterally along the plane of the membrane. B.) They frequently flip-flop from one side of the membrane to the other. C.) They occur in an uninterrupted bilayer, with the membrane proteins restricted to the surface of the membrane. D.) They are free to depart from the membrane and are dissolved in the surrounding solution. E.) They have hydrophilic tails in the interior of the membrane.

Microtubules

Ceased organelle movement, inhibited cell division, prevention of formation of cilia and flagella, and killing of cell will occur when drugs inhibit these. (ALL OF THE ABOVE)

Actin Filaments and Myosin

Contraction of muscle cells depends on what cellular structures?

Increase the rate of a reaction without being consumed by the reaction

Enzymes are described as catalysts, which means that they_____. A.) increase the free energy of the reactants to make the reaction go faster. B.) can alter the free energy change (ΔG) for a chemical reaction. C.) provide activation energy for the reactions to facilitate. D.) are proteins. E.) increase the rate of a reaction without being consumed by the reaction

increase the rate of a reaction without being consumed by the reaction.

Enzymes are described as catalysts, which means that they_____. A.) increase the free energy of the reactants to make the reaction go faster. B.) can alter the free energy change (ΔG) for a chemical reaction. C.) provide activation energy for the reactions they facilitate. D.) are proteins. E.) increase the rate of a reaction without being consumed by the reaction.

4

For each glucose oxidized by cellular respiration, how many molecules of CO2 are released in the citric acid cycle?

Digestion

Function of a central vacuole.

The cells shrivel up because water leaves the cells

If red blood cells are taken from the body and placed in a hypertonic solution, what happens to the cells?

Turgor pressure builds up in the cells

If you forget to water your favorite plant, all of the following will occur at a cellular level except: A.) Water moves out of the cytosol by osmosis B.) Water moves out of the vacuole by osmosis C.) Turgor pressure builds up in the cells D.) The plasma membrane shrinks away from the cell walls E.) Plasmolysis occurs

Free energy

In exergonic reactions, the reaction proceeds with a net release of __________.

Transport proteins provide a hydrophilic route for the solute to cross the membrane.

In facilitated diffusion, what is the role of the transport protein? A.) Transport proteins provide a protein site for ATP hydrolysis, which facilitates of a solute across a membrane. B.) Transport proteins provide a hydrophilic route for the solute to cross the membrane. C.) Transport proteins organize the phospholipids to allow the solute to cross the membrane. D.) Transport proteins provide energy for diffusion of the solute. E.) Transport proteins provide a channel for lipid molecules to cross the membrane.

6

Look at the diagram of an animal cell, which one can transport the substance from cis to trans face? A.) 9 B.) 5 C.) 6 D.) 1 E.) 13

Golgi Bodies

Researchers have been able to study the pathway of a secreted protein by "tagging" it with a fluorescent marker. Using this method, you would observe fluorescence moving from the ER to which organelle? A) nuclear membrane B) lysosome C) plasma membrane D) mitochondria E) Golgi bodies

Golgi

Small vesicles budded off rough ER are transported to _______.

lipid; protein

The ________ portion of the cell membrane is responsible for the isolating functions of the membrane, while the ________ portion regulates exchange and communication with the environment. A) lipid; protein B) cholesterol; lipid C) protein; cholesterol D) carbohydrate; lipid E) None of these

Motor proteins

The cilia and flagella of eukaryotic cells consist of _______.

The types of transport proteins in the membrane.

The permeability of a biological membrane to a specific polar solute may depend on which of the following? A.) The amount of cholestorol in the membrane. B.) The types of transport proteins in the membrane. C.) The phospholipid composition of the membrane. D.) The presence of unsaturated fatty acids in the membrane. E.) The types of polysaccharides present in the membrane.

Rigid Cell Wall

The presence of this distinguishes between a prokaryotic and eukaryotic cell.

Contributes to the cell membrane potential

The sodium-potassium pump is called an electrogenic pump because it _______. A.) pumps equal quantities of Na+ and K+ across the membrane. B.) pumps hydrogen ions out of the cell. C.) contributes to the cell membrane potential. D.) is used to drive the transport of other molecules against another gradient. E.) ionizes sodium and potassium ions.

All of these

Transport processes (for example, diffusion and active transport) occur across which of the following membranes? A) plasma membranes B) chloroplast membranes C) mitochondrial membranes D) ER membranes E) all of these

plant cell contents push hard cell wall

Turgor pressure occurs when _______. A.) plant cell wall pushes extracellular fluid. B.) plant cell contents push hard cell wall. C.) animal cytoplasm pushes cell membrane. D.) animal cell wall pushes cell contents. E.) bacterial cells push cell walls.

Entropy of the universe

Whenever energy is transformed, there is always an increase in the:

Plasmodesmata

Which of following is the intercellular junction in plant cells? A.) Plasmodesmata B.) Tight junctions C.) Desmosomes D.) Gap junctions E.) None of the above

Simple diffusion

Which of following transport doesn't need special protein? A) facilitated diffusion B) simple diffusion C) sodium-potassium pump D) sucrose-hydrogen co-transporter E) receptor-mediated endocytosis

Both are hypothesized to be evolved from the engulfed prokaryotes

Which of the following are common traits of chloroplast and mitochondria? A) Both are capable of cellular respiration. B) Both capture the energy of sunlight to meet metabolic demands. C) Both possess their linear DNA. D) Both are surrounded by a single cell membrane E) Both are hypothesized to be evolved from the engulfed prokaryotes

Aquaporin

Which of the following is channel protein? A.) Proton pump B.) Na+-K+ pump C.) Sucrose-H+ contransporter D.) Aquaporin E.) None of the above

Phagocytosis

Which of the following is the cell eating process by using psuedopods? A.) Phagocytosis B.) Pinocytosis C.) Receptor-mediated endocytosis D.) Exocytosis E.) A,B and C

The contents of a red blood cell are hypertonic to distilled water.

Which statement is correct? a) A solution of seawater is hypertonic b) The contents of a red blood cell are hypertonic to distilled water. c) A solution of distilled water is hypotonic d) Both A and B e) all of the above