cellular respiration

what is cellular respiration

the process by which organic molecules, taken in as food, are broken down in the cells to release energy for the cell’s activities

what is the cellular respiration equation

C₆H₁₂O₆ +6 O₂ ——>6 CO₂+ 6 H₂O - glucose + oxygen → carbon dioxide and water

how much of the energy released from the complete breakdown of glucose is released as heat

60%

why do we need heat energy

because heat is constantly lost to the environment and we need to maintain our body temperature to maintain homeostasis

what is ATP

adenosine triphosphate
composed of adenosine (adenine and ribose sugar) and 3 phosphate groups

how is ATP formed

when a phosphate group joins to a molecule of ADP - adenosine diphosphate

How does ATP work

it transports energy from cellular respiration in the easily broken bond between the second and third phosphate group
adding the phosphate group to make ATP needs energy, then that energy is released elsewhere

what is glycolysis

the first step of cellular respiration, glucose is broken down in 10 steps into 2 molecules of pyruvate

what are the two types of cellular respiration and what differentiates them

aerobic - needs oxygen
anaerobic - doesn’t need oxygen

how does anaerobic respiration work

the pyruvate is fermented into lactic acid in the cytosol as lactic acid is less toxic

what is the yield

2 ATP used up in glycolysis → 4 ATP produced → net 2ATP

why do we need anaerobic respiration

during physical activity our body can’t supply us with enough oxygen to meet energy demands

why is lactic acid bad

because it is still toxic it causes cramps and muscle soreness

what happens after vigorous exercise

the lactic acid is taken by the blood to the liver where it can recombine with oxygen to form glucose and glycogen

we need oxygen for this so we breathe heavily after exercise, this is called repaying our oxygen debt with recovery oxygen

what are the steps of aerobic respiration with their ATP output

glycolysis 2ATP → krebs cycle 1ATP per pyruvate → electron transport system 12-17ATP per pyruvate

ATP total yield from aerobic respiration

up to 38ATP

explain the structure of a mitochondrion

outer membrane, and inner folded membrane called a cristae, to increase surface area

aerobic transformation

pyruvate enters mitochondrial matrix and carbon dioxide removed as it is joined with coenzyme A to make acetyl coenzyme A

Krebs cycle

carbon atoms are released as carbon dioxide alongside release of hydrogen, also known as citric acid cycle

electron transport system

Electrons move through proteins in the mitochondria, creating a proton gradient. This gradient powers ATP production, and oxygen accepts the electrons and protons to form water.