UCONN BIOL 1107 LAB Metabolism II

In the absence of oxygen, anaerobic fermentation allows glycolysis to continue by regenerating which critical coenzyme?

NAD+

Which two enzymes catalyze the step-by-step conversion of pyruvate to ethanol during yeast fermentation?

Pyruvate decarboxylase and alcohol dehydrogenase

Why does yeast produce carbon dioxide gas faster when provided with monosaccharides compared to disaccharides, and how does adding Lactaid affect lactose fermentation?

Monosaccharides enter glycolysis directly, whereas disaccharides require enzymatic cleavage into monosaccharides first; Lactaid supplies lactase to break down lactose into glucose and galactose

What is the optimal incubation temperature for yeast fermentation determined in Lab 9, and what happens to yeast enzymatic activity at 100°C?

45 degrees C; enzymes denature at 100°C due to excessive heat

Which set of histological features uniquely identifies skeletal muscle tissue under a light microscope?

Elongated, cylindrical cells with visible striations and multiple nuclei pushed to the cell edges

What structural feature joins adjacent cardiac muscle cells to synchronize electrical signaling and contractions?

Intercalated discs

Where is smooth muscle tissue located, and what are its characteristic morphological features?

In the walls of internal organs and blood vessels; spindle/teardrop-shaped, non-striated cells with a single central nucleus

Which sequence correctly traces the flow of deoxygenated blood entering the heart from the body until it reaches the lungs?

Vena Cava > Right Atrium > Tricuspid Valve > Right Ventricle > Pulmonary Valve > Pulmonary Trunk/Arteries

What is the correct sequential order of electrical impulse transmission through the cardiac conduction system?

SA Node > AV Node > Bundle of His > Bundle Branches > Purkinje Fibers

On an ECG trace, what cardiac electrical events are represented by the P wave and the QRS complex, respectively?

Atrial depolarization; Ventricular depolarization

Fermentation helps regenerate stores of _____, which allows glycolysis to continue.

NAD⁺

This type of fermentation will create CO2 as a byproduct.

alcohol fermentation

Human muscle cells undergo this type of fermentation during intense exercise.

lactic acid fermentation

Yeast cells undergo this type of fermentation.

alcohol fermentation

Fermentation is the same process as anaerobic respiration.

False

How many classes of tissue are there?

4

Which muscle type is used in voluntary movement?

skeletal

Which muscle type is multinucleated?

skeletal

Which muscle type does not have striations?

smooth

This muscle type is multinucleated, and the nuclei are pushed to the sides of the cell.

skeletal

This muscle type is striated and has dense areas of tissue, called intercalated discs, that link individual cells together.

cardiac

The human heart has this many chambers.

4

Deoxygenated blood is delivered to the heart through the...

inferior and superior vena cavae

The ______ separates the left atrium from the left ventricle.

bicuspid valve

Deoxygenated blood is brought to the lungs through the ______.

pulmonary artery

When blood enters the heart, the first chamber that it enters is the _____.

right atrium

This signal on the ECG represents the contraction of the ventricles.

QRS complex

This signal on the ECG represents the contraction of the atria.

P wave

This signal on the ECG represents the amount of time it takes the electrical signal to travel from the SA node to the AV node, and it includes the amount of time that the electrical signal is delayed by the AV node.

PR segment

Identify structure A

left atrium

Identify structure B.

right ventricle

Identify structure C

aorta

Identify structure D

left ventricle

Identify structure E.

pulmonary artery

Identify structure F

pulmonary vein

Which stage(s) of cellular respiration can occur even when molecular oxygen (O2) is not available?

Glycolysis

In anaerobic respiration, what is the final electron acceptor?

NAD+

What is the optimal temperature for yeast fermentation?

45 °C

Which muscle tissue(s) have no visible striations?

Smooth

In the nested tube fermentation setup, why is the tube quickly inverted after it is sealed?

To trap produced CO2 as a measurable gas bubble

Why do we measure the change in the volume of gas in the test tubes?

To estimate the rate of fermentation

Which carbohydrate would most likely require enzymatic hydrolysis before yeast can efficiently metabolize it?

Maltose

Which result would best support the conclusion that yeast possesses enzymes to metabolize a disaccharide?

The amount of CO2 produced is comparable to a monosaccharide trial

Why was Lactaid added to the tube containing lactose?

To break down lactose into simpler sugars

A student plots CO2 production (mL) for several carbohydrate treatments. Which graph type is most appropriate?

Bar graph

Which microscopic features most clearly differentiates cardiac muscle from skeletal muscle?

Branching fibers with distinct dark lines between the cells (intercalated discs)

Which structure prevents backflow of blood from the left ventricle into the left atrium?

Bicuspid valve

Which muscle type is striated and multinucleated?

Skeletal muscle

Which muscle type consists of tapered cells and lacks striations?

Smooth muscle

Why do yeast cells typically ferment monosaccharides faster than disaccharides?

Disaccharides must be hydrolyzed before entry into glycolysis

Which of the following is a monosaccharide?

Glucose

Identify Structure A

aorta

Identify Structure B

right atrium

Identify Structure C

pulmonary artery

Identify Structure D

left ventricle