cell energy Essay

Submitted By mike718
Words: 971
Pages: 4

Associate Program Material

Cell Energy Worksheet

Answer the following questions:

Cellular respiration:

What is cellular respiration and what are its three stages? Cellular respiration is the set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The three stages of this process are 1) Glycolysis: the cytoplasm 2) Krebs Cycle/The Citric Acid Cycle: mitochondria 3) Electron Transport Chain: the mitochondria (specifically, the inner mitochondrial membrane).

What is the role of glycolysis? Include the reactants and the products. Where does it occur? Glycolysis involves the oxidative breakdown of one glucose into two pyruvate with the capture of some energy as ATP and NADH. Glycolysis is important in the cell because glucose is the main source of fuel for tissues in the body. Glycolysis takes place In the cytosol which is the fluid in which the organelles of the cytoplasm are suspended.

What is the role of the citric acid cycle? Include the reactants and the products. Where does it occur? The citric acid cycle is the final common pathway for the oxidation of fuel molecules—amino acids, fatty acids, and carbohydrates. It functions as hubs to facilitate traffic flow. The citric acid cycle is the biochemical hub of the cell, oxidizing carbon fuels, usually in the form of acetyl CoA, as well as serving as a source of precursors for biosynthesis.

What is the role of the electron transport system? Include the reactants and the products. Where does it occur? Electron transport chains are redox reactions that transfer electrons from an electron donor to an electron acceptor. The transfer of electrons is coupled to the translocation of protons across a membrane, producing a proton gradient. The proton gradient is used to produce useful work.


What is the overall goal of photosynthesis? Photosynthesis is simply the process by which organisms convert solar energy to chemical energy. This is an energy requiring reaction - the energy source is sunlight. The goal is to trap sunlight energy and store it as chemical energy to use in all life functions.

Because photosynthesis only occurs in plants, why is it essential to animal life? The process of photosynthesis provides plants with the food and energy they need to grow. The animals subsequently eat them at various stages of their growth. Photosynthesis is the driving force of primary producers.

What is the role of the light reactions? Include the reactants and the products. Where does it occur? e light reactions use light energy to produce ATP and NADPH. The molecules that function in the light reactions are built into the thylakoid membrane. This equipment includes two complexes called photosystem I (PSI) and photosystem II (PSII). Each photosystem has many chlorophyll molecules along with other pigment molecules and proteins. One particular chlorophyll molecule of each photosystem is located in a region called the reaction center, where the energy absorbed from light initiates a transfer of electrons to other molecules.

What is the role of the Calvin cycle? Include the reactants and the products. Where does it occur? The Calvin cycle has four main steps: carbon fixation, reduction phase, carbohydrate formation, and regeneration phase. Energy to fuel chemical reactions in this sugar-generating process is provided by ATP and NADPH, chemical compounds which contain the energy plants have captured from sunlight.


Explain how photosynthesis and cellular respiration are linked within ecosystems. Photosynthesis is the process by which carbon dioxide, water and light is converted into glucose. This process supplies the bulk of the energy in most ecosystems. An example of this is that plants are usually at the bottom of the food chain. Cellular respiration is the conversion of energy (stored in