Biology Chapter 9 Flashcards

Questions and Answers

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

Reduced

Neutral

Oxidized (correct)

Ionized

When a molecule of NAD+ gains a hydrogen atom (not a hydrogen ion), the molecule becomes

Reduced (correct)

Neutral

Oxidized

Ionized

The ATP made during glycolysis is generated by

Photophosphorylation

Substrate-level phosphorylation (correct)

Cyclic phosphorylation

Oxidative phosphorylation

The oxygen consumed during cellular respiration is involved directly in which process or event?

Accepting electrons at the end of the electron transport chain Signup and view all the answers

An electron loses potential energy when it

Shifts to a more electronegative atom Signup and view all the answers

Why are carbohydrates and fats considered high energy foods?

They have a lot of electrons associated with hydrogen Signup and view all the answers

During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is

Retained in the pyruvate Signup and view all the answers

In addition to ATP, what are the end products of glycolysis?

NADH and pyruvate Signup and view all the answers

Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Most of the free energy available from the oxidation of glucose remains in pyruvate Signup and view all the answers

Starting with one molecule of glucose, the net products of glycolysis are

2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O Signup and view all the answers

In glycolysis, for each molecule of glucose oxidized to pyruvate,

2 molecules of ATP are used and 4 molecules of ATP are produced Signup and view all the answers

A molecule that is phosphorylated:

Has an increased chemical reactivity; it is primed to do cellular work Signup and view all the answers

Which kind of metabolic poison would most directly interfere with glycolysis?

An agent that closely mimics the structure of glucose but is not metabolized Signup and view all the answers

Why is glycolysis described as having an investment phase and a payoff phase?

It uses stored ATP and then forms a net increase in ATP Signup and view all the answers

Study Notes

Oxidation-Reduction Reactions

A glucose molecule becomes oxidized when it loses a hydrogen atom during oxidation-reduction reactions.
NAD+ is reduced when it gains a hydrogen atom, contributing to cellular respiration.

Glycolysis Overview

ATP is produced during glycolysis through substrate-level phosphorylation.
The end products of glycolysis include 2 NADH, 2 pyruvate, 2 ATP, and 2 H2O.

Role of Oxygen

Oxygen is directly involved in accepting electrons at the end of the electron transport chain during cellular respiration.

Electron Energy and Metabolism

Electrons lose potential energy when shifting to more electronegative atoms, driving metabolic processes.
Carbohydrates and fats are considered high-energy foods due to the abundance of electrons associated with hydrogen atoms.

Energy Retention in Glycolysis

Most of the energy from glucose catabolism is retained in pyruvate during glycolysis.
Despite significant energy potential, only two molecules of NADH are generated due to energy retention in pyruvate.

Glycolysis Phases

Glycolysis consists of an investment phase that utilizes 2 ATP and a payoff phase that produces 4 ATP, resulting in a net gain of 2 ATP.

Phosphorylation

Phosphorylation increases a molecule's chemical reactivity, preparing it for cellular work.

Metabolic Inhibitors

Metabolic poisons that mimic glucose structure but are not metabolized can directly interfere with glycolysis.

Energy Balance in Glycolysis

From one molecule of glucose, 2 ATP are consumed, and 4 ATP are produced during glycolysis, resulting in a net increase.

Description

Test your knowledge of key concepts from Biology Chapter 9 with these flashcards. Explore terms related to cellular respiration, oxidation-reduction reactions, and ATP generation. Perfect for students preparing for exams or wanting to reinforce their understanding.