Organisation Flashcards
Explain organisational hierarchy
The tiers of organisation that are used to class the size and type of biological organisms
organism organ system organ tissue cells subcellular structures
Define a cell, tissue, organ and organism
organism - the combination of several organ systems to make one independent living creature (eg, a human)
organ system - the combination of several similar organs that all serve different functions but towards the same goal (ex, small intestine, stomach, and pancreas are all in the digestive system)
organ- the combination of many different tissues to serve a certain function (eg, the heart, made up of lots of different tissues to serve one main function - pump blood around the body)
tissue - a group of cells that are all similar and serve simple functions
cells - the building blocks of life. they make up all living things - plants, animals, and bacteria. contain subcellular structures and there are many different types, each serving their own particular function. most are specialized so that they can perform their own function efficiently
Know that digestive system is an example of an organ system in which several organs work together to digest and absorb food.
an organ system is the combination of several similar organs that all serve different functions but towards the same goal (ex, small intestine, stomach, and pancreas are all in the digestive system)
- Explain how diffusion , osmosis and active transport are used in the digestive system
The absorption of nutrients in the small intestine relies heavily on diffusion. tiny, broken down forms of food are absorbed by villi in the small intestine wall, and into the bloodstream. They passively transport through the permeable cell membrane along the concentration gradient, because there is a higher concentration outside the villi than inside.
Osmosis occurs in the large intestine, where a concentration gradient forms against the high salt concentrated blood outside the large intestine and the low salt concentration mixture inside the large intestine. Since osmosis is the transportation of water along the concentration gradient, water moves from the mixture remaining in the large intestine and into the blood.
Mostly, there are more nutrients inside the gut than in the blood, however, sometimes the concentration gradient is the wrong way round, meaning the concentration is higher inside the blood than inside the gut. This means that due to passive transport and diffusion, the nutrients would pass from the blood into the gut. This is not what the body wants, so used active transport to prevent this from happening and allow nutrients to move against the concentration gradient. Active transport requires the use of energy to move particles from low concentration to high concentration. Cells that do this require lots of energy, so hence have lots of mitochondria to do this.
Relate knowledge of enzymes to Metabolism
Enzymes are biological catalysts that break down large food molecules into smaller particles of nutrients, that can consequently be absorbed into the bloodstream. Without enzymes, the food we eat would never be broken down so that it can be absorbed, and hence we would never get any nutrients and become malnourished.
Describe the structure-function and optimum conditions for enzymes
All enzymes have optimum conditions that they work best in, and that is a combination of pH and temperature. When these optimum conditions are met for the enzymes, they will work their most efficient and digest the most food. Enzymes activity can also depend upon enzyme concentration and substrate concentration.
Define denaturation
Denaturing is the process of enzymes essentially dying, where through being exposed to too high temperatures or too acidic solutions, their active site becomes shrivelled and beyond repairable. A denatured enzyme cannot be fixed or reversed
Recall the sites of production and the action of amylase, proteases and lipases.
Amylase - Small intestine, salivary glands and pancreas. Breaks down carbohydrates into glucose
Lipase - Pancreas and small intestine. Breaks down lipids/fats into fatty acids and glycerol
Protease - Small intestine, pancreas and stomach. breaks down proteins into amino acids
Know that digestive enzymes convert food into small soluble molecules that can be absorbed into the bloodstream.
the process of digestion is enzymes breaking down large food molecules into smaller, soluble nutrients that can be absorbed into the blood via the villi in the small intestine. without enzymes, the food molecules would be too big to fit through the membrane of the villi, and simply pass through the body and be excreted as faeces
State that the products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
The products of digestion are used everywhere in the body. Amino acids release energy and form new proteins. Glucose is used for respiration and turned into glycogen.
Recall where bile is made and stored and its pH and function
Bile is made in the liver and stored in the gallbladder, transported there via the bile ducts. it’s slightly acidic. Its job is to balance the pH of the small intestine to slightly alkaline, which helps lipase digest fats. it also helps to emulsify fats which speeds up digestion.
State conditions that increase the rate of fat breakdown by lipase.
presence of bile which regulates the pH to lipase’s optimum of 7-8, the biological body temperature of 37.5°C
concentration of lipase enzyme
concentration of lipids and fats
