Test 2 Flashcards
True or false:
Enzymes are catalysts that convert positive 🔺G reactions to negative 🔺reactions
False
What is true concerning exerting pathways?
They are frequently coupled to endergonic pathways vía an energy coupler called ATP
What would yield the most energy per gram when oxidized?
Fat
What would involve a decrease of entropy within the system?
Dehydration synthesis of a protein from 20 different amino acids
What is the net change in free energy (🔺G) for a reaction that has reached chemical equilibrium?
No bet change (🔺G=0)
What is the most randomized form of energy?
Heat
According to the second law of thermodynamics
The entropy of the universe is constantly increasing
How does ATP make a chemical reaction go?
By the formation of a phosphorylated intermediate compound which is lore reactive
A chemical reaction that has a positive 🔺G is correctly described as
Endergonic
The phrase “enzymes are specific” means what?
Enzymes have specific environments wherein they can effectively catalyze reactions, and enzymes interact only with specific cellular substrates when catalyzing reactions
What best describes chemical equilibrium?
Reactions continuing with no effect on the concentrations of reactants and products
Which organelle can convert light energy into a chemical reaction?
Chloroplast
True or false: lysosomes are Involved in protein synthesis
False
What is found in an animal cell, but not in a bacteria cell?
Endoplasmas reticulum (ER)
What does not require ATP energy?
The diffusion of ions into a cell
What component is present in all prokaryotic and eukaryotic cells (in other words all living cells)?
Ribosomes
What type of cell would probably provide the best opportunity to study lysosomes?
Phagocytes white blood cells
Which organelle contain some of their own DNA and ribosomes?
Mitochondria and chloroplasts
Which organelles are more common in cells that are heavily i volver with the synthesis and excretion of steroids
Smooth endoplasmic reticulum
Lysosomal enzymes originate as raw material in the —— but are modified, packaged, sorted and targeted bf the
Rough ER/golgi apparatus
True or false: chloroplast is involved in the endomembrane system
False
Describe the most common route for membrane flow through the endomembrane system for a protein that is to be secretes
Rough ER ➡️ Transport vesicle ➡️ golgi apparatus ➡️ transport vesicle ➡️ plasma
Large numbers of ribosomes are present in cells that specialize in producing
Proteins
What would diffuse directly through the phospholipid bilateral of a plasma membrane most rapidly?
CO2
Glucose
An amino acid
Starch
Sucrose
Na+ and K+
CO2
How many oxygen molecules are required in the fermentation of one molecule of glucose to ethyl alcohol
And CO2?
0
According to the fluid mosaic model of cell membranes, which if the following is a true statement about membrane phospholipids?
They can move laterally along the plane of the membrane
A human red blood cell that is added up to a hypotonic solution will
Take up water and swell
Which membrane bound molecules are thought to be most important in cell-cell recognition?
Glycoproteins
Use of energy by cells to move a solute from an area of low concentration to an area of higher concentration of that solute describes what process or condition?
Active transport
A series of enzymes catalyzes the series of reactions X ➡️ Y ➡️ Z ➡️ A. Product “A” bunds to the enzyme that converts X to Y at an allosteric site. This binding decreases the activity of the enzyme. In this example substance, A functions as
A non competitive inhibitor
If electron micrographs consistently show mitochondria to be grouped around a certain structure in a certain kind of cell, one might logically infer that the
Structure requires considerable supply of energy
A biologist grinds your some plant cells and then centrifuges the mixture. Some membrane bound organelles settled in the bottom of the centrifuge tube. These organelles were then isolated for the experimentation. During the experiments it was found that some organelles took up O2 and gave off CO2. These organelles must be
Mitochondria
Fructuose is a 6 carbon sugar that does not diffuse through phospholipid bilayers of cell membranes. However, in humans the epithelial cells lining the small intestines readily move fructose from the fructose rich intestinal lumen into the intestinal epithelial cells?
Facilitated diffusion
Cations cross cell membranes and enter cells ____
By traveling down electrochemical gradients
True or false: assuming one beaker has glucose and does cellular respiration, and a cell contains the same quantity of glucose, the beaker combustion releases more calories if energy from glucose than does cellular respiration
False
During the complete metabolism of 1 molecule of glucose by a eukaryote, about how many ATP molecules are thought to be produced by the processes called substrate level phosphorylation and oxidative phosphorylation?
About 32
What is fermentation and what does it do?
It allows glycolysis and ATP production to continue when no oxygen is available, and it provides a mechanism to regenerate NAD+ from NADH when no oxygen is available
True or false: the lactate femrentation process produces 2 extra ATP molecules in addition to the 2 ATPs produced by the glycolysis pathway for a net gain of 4 ATP molecules
False
True or false: the end products of glycolysis pathway are CO2 and H2O
False
How would you best describe the mechanism of chemiososmosis in cellular respiration?
It is the release of energy to make ATP by way of facilitated diffusion of H+ across membranes
A muscle cell during oxygen deprivation converts pyruvate to _____ and in this step the call regains _____ which allows glycolysis to continue
Lactate/NAD+
A fatty acid molecule is partially oxidized to form 10 molecules of acetyl CoA. Starting with these 10 acetyl CoA molecules, how many molecules of ATP will be made by substrate level phosphorylation in the citric acid cycle?
10
The primary function of the mitochondrion is the production of ATP. To carry out this function, a mitochondrion must vi rain all of the following EXCEPT
-The membrane bound electron transport chain
-glycolysis enzymes
-citric acid cycle enzymes
-ATP synthase
-proton pumps embedded in an inner membrane
Glycolysis enzymes
The ATP made during glycolysis is generated directly by which of the following processes
Substrate level phosphorylation
The chemiosmotic mechanism which releases energy to make ATP takes place
When H+ crossed the inner mitochondrial membrane by facilitated diffusion
In the chemical reaction represented in the bold type below, which molecules will be reduced and which will be oxidized when the reaction occurs?
C6H12O6 + 6O2 ➡️ 6CO2 + 6HO2
C6H12O6 is being oxidized, and O2 is being reduced
Which of the following is a reasonable explanation for how unsaturated fatty acids help keep membranes more fluid during periods of lower temperature?
The double bonds form kinks in the fatty acids, preventing adjacent lipids from packaging tightly
Celery stalks immersed in fresh water for several hours become stiff and hard. Conversely stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the celery stalks are
Hypertonic ti fresh water but not hypotonic to the salt solution
You eat a cheeseburger and a fresh salad with French dressing. Which of the following un your food are generally not oxidized in the aerobic cellular respiration pathway to generate ATP?
Cellulose
You have a friend who went on a diet and exercise and burned off 15 pounds of fat. Where did the fat biomass go?
It was released from the body as CO2 and H2O
Proteins called electrogenic pumps (proton pumps) found in the cell membranes of the plant vascular tissues
Generate a H+ gradient so that the sucrose can enter cells via a Sucrose H- cotransporter
Mammalian blood contains the equivalent of a 0.15 M NaCI. Seawater contains the equivalent of 0.45 M NaCI. What will happen if red blood cells are transferred to seawater?
Water will leave the cells, causing them to shrivel and collapse.
By way of the electrochemical gradient which of the following can cross cell membranes to enter cells?
Ca+
