What is cellular Respiration?

Question

I am extremely confused on what cellular respiration really is and how it works. Can someone please explain in kid-friendly terms on whats going on? How does it differ from Photosynthesis?

Answer 1

It difers from photosynthesis in that it occurs in humans and animals and NADPH is found in photosynthesis while in celluar respiration NADH

Cellular respiration is a process that describes the metabolic reactions and processes that take place in a cell to obtain chemical energy from fuel molecules. Energy is released by the oxidation of fuel molecules and is stored as "high-energy" carriers. The reactions involved in respiration are catabolic reactions in metabolism.

Fuel molecules commonly used by cells in respiration include glucose, amino acids and fatty acids, and a common oxidizing agent (electron acceptor) is molecular oxygen (O2). There are organisms, however, that can respire using other organic molecules as electron acceptors instead of oxygen. Organisms that use oxygen as a final electron acceptor in respiration are described as aerobic, while those that do not are referred to as anaerobic.

The energy released in respiration is used to synthesise molecules that act as a chemical storage of this energy. One of the most widely used compounds in a cell is adenosine triphosphate (ATP) and its stored chemical energy can be used for many processes requiring energy, including biosynthesis, locomotion or transportation of molecules across cell membranes. Because of its ubiquitous nature, ATP is also known as the "universal energy currency", since the amount of it in a cell indicates how much energy is available for energy-consuming processes.

Photosynthesis (photo=light, synthesis=putting together), generally, is the synthesis of sugar from light, carbon dioxide and water, with oxygen as a waste product. It is arguably the most important biochemical pathway known; nearly all life depends on it. It is an extremely complex process, comprised of many coordinated biochemical reactions. It occurs in higher plants, algae, some bacteria, and some protists, organisms collectively referred to as photoautotrophs.

Most plants are photoautotrophs, which means that they are able to synthesize food directly from inorganic compounds using light energy - for example from the sun, instead of eating other organisms or relying on nutrients derived from them. This is distinct from chemoautotrophs that do not depend on light energy, but use energy from inorganic compounds.

The energy for photosynthesis ultimately comes from absorbed photons and involves a reducing agent, which is water in the case of plants, releasing oxygen as a waste product. The light energy is converted to chemical energy (known as light-dependent reactions), in the form of ATP and NADPH, which is used for synthetic reactions in photoautotrophs. Most notably plants use the chemical energy to fix carbon dioxide into carbohydrates and other organic compounds through light-independent reactions. The overall equation for carbon fixation (sometimes referred to as carbon reduction) in green plants is

n CO2 + 2n H2O + ATP + NADPH → (CH2O)n + n H2O + n O2,
Where n is defined according to the structure of the resulting carbohydrate.
More specifically, carbon fixation produces an intermediate product, which is then converted to the final hexose carbohydrate products. These carbohydrate products are then variously used to form other organic compounds, such as the building material cellulose, as precursors for lipid and amino acid biosynthesis or as a fuel in cellular respiration. The latter not only occurs in plants, but also in animals when the energy from plants get passed through a food chain. Organisms dependent on photosynthetic and chemosynthetic organisms are called heterotrophs. In general outline, cellular respiration is the opposite of photosynthesis: glucose and other compounds are oxidised to produce carbon dioxide, water, and chemical energy. However, both processes actually take place through a different sequence of reactions and in different cellular compartments.

Plants absorb light primarily using the pigment chlorophyll, which is the reason that most plants have a green color. The function of chlorophyll is often supported by other accessory pigments such as carotenes and xanthophylls. Both chlorophyll and accessory pigments are contained in organelles (compartments within the cell) called chloroplasts. Although all cells in the green parts of a plant have chloroplasts, most of the energy is captured in the leaves. The cells in the interior tissues of a leaf, called the mesophyll, contain about half a million chloroplasts for every square millimeter of leaf. The surface of the leaf is uniformly coated with a water-resistant, waxy cuticle, that protects the leaf from excessive evaporation of water and decreases the absorption of ultraviolet or blue light to reduce heating. The transparent epidermis layer allows light to pass through to the palisade mesophyll cells where most of the photosynthesis takes place.

Answer 2

Photosynthesis and cellular respiration work as a cycle

Photosynthesis takes light energy and converts it into sugar that the body needs. In cellular respiration, the body takes this sugar and converts it back into energy (ATP) which the body then uses in certain bodily functions.

Here, look at the formulas for photosynthesis and respiration:

Photosynthesis:
Carbon dioxide + water + energy (sunlight) >>> Glucose + oxygen

Respiration:
Glucose + oxygen >>> carbon dioxide + water + energy (ATP)

See how they're the same equation, just reversed? Hope that helps a little

Answer 3

The exchange of O2 and Co2+H2O at lung level is External Respiration.At the cellular level, at Cytoplasm & Mitochondria,O2 combining with carbon compounds and to forming CO2+H2O (through Glycolytic &Kreb's cycles) C6H12O6+6O2-> 6CO2+6H2O+Energy is Cellular respiration.

Answer 4

Photoynthesis- plants making their own food
Cellular Respiration (commonly called Respiration)- using food made (for plants) or from diet (for animals) to make energy.
Only plants do photosynthesis, plants and animals do respiration because however the food is obtained, its needed to make energy. That's the energy that plants and animals use to grow etc. Respiration occurs mainly with oxygen. Plants need carbon dioxide, water and energy from the sun to do photosynthesis

Hope you got it!

Answer 5

this is how your body makes energy at the cellular level. Your cells get glucose(sugar) from the bloodstream and your mitochondria break it down for energy