Chemical Reactions
This is what we call the starting substances in a chemical reaction.
What are reactants?
These organisms make their own food using sunlight.
What are producers?
This process releases energy from food molecules.
What is cellular respiration?
Energy is stored in these molecules made during photosynthesis.
What are sugars (glucose)?
The products of photosynthesis become the reactants for this process.
What is cellular respiration?
In a chemical reaction, atoms are not destroyed but are instead ___.
What are rearranged?
Photosynthesis takes place in this organelle.
What is the chloroplast?
Cellular respiration mostly takes place in this organelle.
What is the mitochondrion?
This type of energy is stored in the bonds of molecules.
What is chemical energy?
The sun is considered the ultimate source of energy because __.
What is it provides energy for photosynthesis?
Breaking bonds between atoms usually requires this.
What is energy?
These are the reactants of photosynthesis.
What are carbon dioxide, water, and light energy?
These are the reactants of cellular respiration.
What are sugar (glucose) and oxygen?
During photosynthesis, light energy is ___.
What is absorbed and stored?
These microscopic producers are responsible for much of Earth’s oxygen.
What are phytoplankton?
This law states that matter and energy are not created or destroyed in a chemical reaction.
What is the law of conservation of matter and energy?
The main purpose of photosynthesis is to ___.
What is store energy in sugar molecules?
These are the products of cellular respiration.
What are carbon dioxide, water, and energy?
Cells use this released energy to carry out life processes.
What is chemical energy from food?
Explain the relationship between photosynthesis and cellular respiration in one sentence.
Photosynthesis stores energy in sugars, and cellular respiration releases that energy for cells to use.
During a chemical reaction in a cell, energy is required to break bonds and energy is released when new bonds form. Explain why chemical reactions can both absorb and release energy without violating conservation of energy.
Because energy is absorbed when bonds are broken and released when new bonds form, but the total amount of energy before and after the reaction stays the same, so energy is not created or destroyed.
A plant is kept in a dark room for several days. Predict how this will affect the plant’s ability to make food and explain why using the reactants of photosynthesis.
The plant will not be able to make sugar because photosynthesis requires light energy as a reactant, and without light the chemical reactions that produce sugar cannot occur.
Explain why both plants and animals need cellular respiration even though plants can make their own food.
Both plants and animals use cellular respiration to release energy stored in sugar molecules, because energy must be released from food for cells to perform life processes.
A molecule of glucose is broken down during cellular respiration. Describe what happens to the atoms in the glucose molecule and what happens to the energy stored in its bonds.
The atoms in glucose are rearranged to form carbon dioxide and water, and the energy stored in the bonds is released for the cell to use.
Explain how photosynthesis and cellular respiration together cycle both matter and energy in living systems.
Photosynthesis stores energy by using carbon dioxide and water to make sugar and oxygen, while cellular respiration uses sugar and oxygen to release energy and produce carbon dioxide and water, cycling matter and energy through living systems.