Answer:
In addition to glucose, animals can also derive energy from other macromolecules such as fats and proteins through different metabolic pathways.
Step-by-step explanation:
Plants, such as sunflowers, and animals process energy through different mechanisms. In plants, the process of energy conversion is primarily carried out through photosynthesis, while animals obtain energy through various metabolic processes.
Photosynthesis in Plants:
Photosynthesis is a complex biochemical process that occurs in the chloroplasts of plant cells. It involves the conversion of light energy from the sun into chemical energy in the form of glucose. The process can be summarized in the following steps:
1. Light Absorption: Chlorophyll pigments present in the chloroplasts absorb light energy from the sun.
2. Water Splitting: The absorbed light energy is used to split water molecules into oxygen and hydrogen ions.
3. Electron Transport Chain: The released electrons from water are transferred through a series of electron carriers, generating ATP (adenosine triphosphate) molecules.
4. Carbon Fixation: Carbon dioxide from the atmosphere enters the chloroplasts and combines with hydrogen ions to produce glucose through a series of enzymatic reactions known as the Calvin cycle.
5. Glucose Storage: Glucose is either used immediately for energy production or stored as starch for later use.
During photosynthesis, plants also release oxygen as a byproduct, which is vital for supporting animal life on Earth.
Energy Processing in Animals:
Animals, including humans, obtain energy through various metabolic processes that involve breaking down organic molecules obtained from food sources. The primary mechanism for energy processing in animals is cellular respiration, which occurs in the mitochondria of cells. Cellular respiration can be divided into three main stages:
1. Glycolysis: This initial stage takes place in the cytoplasm and involves breaking down glucose into two molecules of pyruvate, producing a small amount of ATP.
2. Citric Acid Cycle (Krebs Cycle): Pyruvate molecules enter the mitochondria and undergo a series of reactions, releasing carbon dioxide and generating ATP and electron carriers (NADH and FADH2).
3. Electron Transport Chain: The electron carriers produced in the previous steps transfer their electrons to the electron transport chain located in the inner mitochondrial membrane. This process generates a large amount of ATP through oxidative phosphorylation.