2-L1++

Where do cell nutrients circulating in the blood primarily come from?

Atmospheric sources
Diet (correct)
Genetic inheritance
Intravenous injections

Which of the following is NOT mentioned as a source of cell nutrients in the text?

Release from storage in body tissues
Diet
Replenishment from the brain (correct)
Synthesis in body tissues

What are some of the physiological situations that can cause changes in the blood concentration of cell nutrients?

Malnutrition and enzyme deficiency states
Fasting and exercise (correct)
Atherosclerosis and shock
Diabetes and obesity

Which tissues are involved in the metabolism of cell nutrients including degradation for energy release?

All tissues (C) Signup and view all the answers

In addition to liver, which other body tissue is mentioned as being involved in the storage of cell nutrients?

Skeletal muscle (B) Signup and view all the answers

What are some of the pathological conditions that can lead to changes in the blood concentration of cell nutrients?

Obesity and malnutrition (A) Signup and view all the answers

What is the main role of ATP and ADP in the cell?

Drive the free energy requiring activities of the cell (D) Signup and view all the answers

What is the difference between ATP and ADP?

Number of covalently-linked phosphate groups (D) Signup and view all the answers

Which molecule acts as a small store of free energy in muscle cells?

Creatine phosphate (A) Signup and view all the answers

When are catabolic pathways activated?

When ATP concentration decreases (B) Signup and view all the answers

Which compound is important in producing ATP from ADP in glycolysis via substrate-level phosphorylation?

Creatine phosphate (B) Signup and view all the answers

What is the function of creatinine in the body?

Has no function and is excreted (C) Signup and view all the answers

What signals the activation of anabolic pathways?

High concentration of ATP (A) Signup and view all the answers

'High-energy signals' such as NADH, NADPH, and FAD2H indicate what in the cell?

Adequate energy levels for immediate needs (C) Signup and view all the answers

Which of the following statements regarding cell metabolism is correct?

Catabolism involves the breakdown of larger molecules into smaller ones, while anabolism involves the synthesis of larger molecules from smaller ones. (A) Signup and view all the answers

Which of the following statements is true regarding biological oxidation?

Oxidation reactions are always accompanied by reduction reactions (REDOX reactions). (D) Signup and view all the answers

What is the function of carrier molecules like NAD+, NADP+, and FAD in cell metabolism?

They act as carriers of reducing power, cycling between oxidized and reduced forms. (B) Signup and view all the answers

What is the relationship between enthalpy change (H) and free energy change (G) in a chemical reaction?

G = H - TS, where T is the temperature in Kelvin. (B) Signup and view all the answers

What is the significance of the standard free energy change (G) in cell metabolism?

It is the free energy change when the temperature is 25C, the concentrations of reactants and products are 1M, and the pH is 7.0. (A) Signup and view all the answers

Which of the following statements about exergonic and endergonic reactions is correct?

Exergonic reactions release energy and can drive endergonic reactions. (D) Signup and view all the answers

Which of the following statements regarding the functions of cell metabolism is correct?

Cell metabolism provides energy for cell function, building block molecules for synthesis of cell components, organic precursor molecules for interconversion, and biosynthetic reducing power. (C) Signup and view all the answers

Which of the following statements about the total concentration of carrier molecules (e.g., NAD+/NADH, NADP+/NADPH) in cells is correct?

The total concentration of carrier molecules is constant, and they cycle between oxidized and reduced forms. (B) Signup and view all the answers

Which of the following statements about the components of carrier molecules like NAD+ and FAD is correct?

The components of carrier molecules, such as nicotinamide and flavin, cannot be synthesized by the body and must be supplied in the diet (as vitamins). (A) Signup and view all the answers