Cell Metabolism and Energy Processes

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Questions and Answers

What is the slope of the log-log relationship between metabolic rate and body mass?

0.75 (correct)

0.67

1.0

0.5

What term is used to describe the physiologically-related mass that changes less rapidly than actual body mass?

Surface area

Body mass

Metabolic mass (correct)

Actual mass

Why is the slope of the log-log relationship considered a compromise?

It reflects only large animals.

It balances between metabolism proportional to mass and surface area. (correct)

It is based on empirical measurements.

It equates metabolism to body length.

What misconception about metabolic rates do many textbooks present?

Smaller animals have a higher metabolic rate per gram of body mass. Signup and view all the answers

Which represents the theoretical slope in four-dimensional space for metabolic rate?

0.75 Signup and view all the answers

What significant mistake is highlighted concerning drug dosage in elephants?

The dosage was excessively high due to a misunderstanding of metabolic rates. Signup and view all the answers

What process is indicated to be proportional to metabolic rate?

Physiological processes Signup and view all the answers

What are the units of 'MASS' indicated in the comparison between the mouse, human, and elephant?

Kilograms Signup and view all the answers

What is the process by which early photosynthetic bacteria converted sunlight into energy?

Anaerobic metabolism Signup and view all the answers

Which of the following methods is not used to measure metabolic rate?

Heart rate monitoring Signup and view all the answers

What happens to oxygen levels in the atmosphere due to the activity of photosynthetic plants over time?

They increase to current levels of 21% Signup and view all the answers

Which of the following factors does not influence metabolic rate?

Dietary preferences Signup and view all the answers

What equation represents the relationship between glucose and oxygen in animal metabolism?

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + 2870 kJ/mole$ Signup and view all the answers

Which statement correctly describes the relationship between body mass and metabolic rate?

Smaller animals have a higher metabolic rate than larger animals. Signup and view all the answers

Which of the following is a correct definition of metabolic rate?

The sum total of all biochemical reactions occurring in the body. Signup and view all the answers

What is the main role of ATP in cells?

To act as a high-energy molecule for energy transfer Signup and view all the answers

Which of the following factors does NOT influence the metabolic rate of animals?

The age of the animal Signup and view all the answers

What is the net useful energy produced from anaerobic metabolism of glucose?

2 ATP Signup and view all the answers

How much total energy is generated from one mole of glucose during aerobic metabolism?

2870 kJ total energy Signup and view all the answers

Which statement best defines animal metabolism?

It is the overall direction of biochemical reactions that define animal life Signup and view all the answers

During anaerobic metabolism, which byproduct is produced from glucose?

Lactate Signup and view all the answers

What is one significant implication of physical laws on biological reactions?

They dictate how energy is exchanged and transformed Signup and view all the answers

Which of the following statements about cell metabolism is accurate?

It encompasses both catabolic and anabolic reactions Signup and view all the answers

What is the slope representing the effect of mass on metabolism across almost all animals?

0.75 Signup and view all the answers

Which of the following factors significantly increases chemical reaction rates?

Higher temperatures Signup and view all the answers

In terms of locomotion, what is a major difference between aquatic and aerial movement?

Both rely on fluid dynamics but utilize different forces Signup and view all the answers

What is the term used to describe the metabolic cost associated with locomotion?

Metabolic grade Signup and view all the answers

Which mechanism is NOT a way for animals to swim?

Gliding Signup and view all the answers

Which animal uses jet propulsion as a means of locomotion?

Jellyfish Signup and view all the answers

How does the metabolic cost of walking or running generally change with speed?

It is typically linear with speed. Signup and view all the answers

What is the Q10 value corresponding to most biochemical reactions?

Approximately 2 - 3 Signup and view all the answers

Which of the following methods is used for powered flight in animals?

Dynamic soaring Signup and view all the answers

Which of the following statements about gliding is true?

It allows an animal to maintain speed with neutral lift. Signup and view all the answers

Study Notes

Cell Metabolism

Involves energy usage through catabolism (breaking down) and anabolism (synthesizing) of organic molecules.
Defines overall animal metabolism, producing heat and is referred to as “THE FIRE OF LIFE”.

Metabolism and Physical Laws

Biochemical reactions governed by physical laws dictate energy exchange and transformation important for biological processes.
Conservation of energy is a core principle; understanding it is essential for biologists.

Metabolic Rates

Influenced by factors: presence of oxygen, activity level, body mass, cellular complexity, phylogeny, and body/ambient temperature.
Metabolic rate measures are varied, including heat production, oxygen consumption, and energy balance.

ATP and Energy

ATP (Adenosine Triphosphate) acts as an energy source, releasing 22 kJ of useful energy per mole when phosphate groups are lost.
Also important for DNA, RNA, and function as a coenzyme.

Anaerobic and Aerobic Metabolism

Anaerobic metabolism generates 2 lactate and 2 ATP from glucose, producing 117 kJ/mole of total energy.
Aerobic metabolism breaks down glucose in the presence of oxygen into carbon dioxide and water, generating 2870 kJ/mole of total energy.

Origin of Oxygen

Early Earth atmosphere lacked oxygen; first photosynthetic bacteria did not use oxygen but synthesized organic molecules from CO2.
Photosynthetic plants produced oxygen over 2 billion years ago, contributing to the current atmospheric level of 21% oxygen.

Measuring Metabolic Rates

Multiple methods available, including heat production, oxygen consumption, carbon dioxide production, and substrate utilization.
Antoine Lavoisier first measured heat production to gauge metabolic rate using an ice jacket method.

Activity Level and Metabolic Rate

Metabolic rate varies widely from minimal/basal to maximal/summit levels.
High physical activity results in increased metabolic rates.

Body Mass and Metabolic Rate

Larger animals generally have a lower metabolic rate per gram than smaller animals, influenced by various scales.
A logarithmic scale relationship shows a slope of 0.75, suggesting a compromise between mass and surface area.

Cellular Grade and Metabolic Rate

Metabolism varies among unicellular organisms, poikilotherms (cold-blooded), and homeotherms (warm-blooded).
The slope of 0.75 applies across most species, regardless of body size.

Impact of Temperature on Metabolism

Higher temperatures accelerate chemical reactions; Q10 describes the proportional increase in reaction rate over a 10°C range.
Biochemical processes typically see a Q10 value between 2-3, indicating significant reaction acceleration with temperature.

Locomotion and Metabolism

Different forms of locomotion (aquatic, terrestrial, aerial) incur varying metabolic costs.
Aquatic movement relies on drag, while aerial movement hinges on lift.

Aquatic Locomotion Strategies

Jet propulsion is utilized by jellyfish and cephalopods; drag from limbs is common in other aquatic animals.
Larger aquatic animals can achieve lift through hydrofoils.

Aerial Locomotion and Flight

Flight requires the generation of lift to counteract weight and drag; parachuting is a primitive flight form utilizing drag.
Gliding employs less energy than powered flight and can be seen in various mammal species.

Powered Flight Evolution

Two main theories for powered flight evolution: ground-up (leaping dinosaurs) and tree-down (gliding mammals).

Running and Walking Mechanics

Limbs act as levers to support body weight and facilitate forward movement, optimized for stability.
The metabolic cost is typically linear with speed and selected gait, remaining independent of speed for efficiency in transport.

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Description

Explore the intricate world of cell metabolism, including catabolism and anabolism, and how they contribute to the overall metabolic rate. Understand the influence of physical laws on biochemical reactions and the role of ATP as an energy currency. This quiz covers both anaerobic and aerobic metabolism to provide a comprehensive understanding of energy transformation in biological systems.