biology end of year

• what is a tissue

  a collection of cells (not necessarily identical) that perform a specific function eg xylem and epithial cells
• what is muscle and what are muscles made up of

  made up of a group of muscle cells forming muscle tissue. a specialised tissue that is able to contract and conduct electrical impulses. they contain large numbers of mitochondria.
• how are muscle tissues kept alive

  blood running through them, supplied through the blood tissue.
• where is smooth uscle found

  inside internal organs
• where is skeletal muscle found

  attached to bones
• where is caridac muscle found


  used in construction of the heart only

  
• what is glandular tissue, where is it and what is it made of

  found throughout the endocrine system, producing vital enzymes and hormones to enable an organism to function properly. they are connected to capillaries and transfer substances produced to desired target.
• what is epithial tissue

  this provides the outside covers for organ surfaces. covers whole surface of body made of cells closely packed in layers. specialised to form covering or lining.
• what is endothelium


  epithelial cell surfaces that cover surfaces on the interior of the body.
• whats an organ


  a combination of tissues that are coordinated to perform a variety of functions.

  
• what is an organ system


  a group of organs that work together to perform a major function
• what are the seven food groups

  fats, minerals, proteins, vitamins, water, fibre, and carbohydrates
• talk about carbohydrates


  glucose breaks them down to carbohydrase eg. amylase

  made in the mouth pancreas and small intstine
• what are carbohydrates made of

  long chains of identical small sugar molecules
• why are the small sugar molecules very useful

  the body breaks these food molecules into single or small chains of sugar molecules which are used for ENERGY
• why do sugars require a specific technique to release the sugar

  because the sugars are held together by chemical bonds
• talk about fats


  theyre for insulation and storage (also for cushioning organs). composed of glycerol and fatty acids,

  broken by lipase enzymes

  produced in pancreas and small intestine
• talk about minerals


  theyre for healthy growth

  dont break down into anything

  example of minerals are iron and calcium

  they help for healthy bodily funterm-21ctions
• talk about water


  keeps cells hydrated

  doesnt break down any further
• talk about fibre


  undigestible walls - cant digest
• talk about proteins


  amino acids break them down to protease, made in the pancreas, small intestine and stomach.
• talk about vitamins


  very important for growth

  usuallly carbon based
• what must food be (that is usually is not already) to dissolve in the blood and be transported

  soluble
• what two digestions does our stomach use

  physical and chemical digestion
• what is physical digestion

  the shape of the food must be physically changed so it can fit through the smaller part of the digestive system
• what is chemical digestion


  useful chemicals can be released and dissolve in the blood. bonds must be broken
• where does food enter in the stomach

  through the gullet
• what does glandular tissue make in the stomach

  hydrochloric acid, mucus and protease enzymes
• what happens in terms of hydrochloric acid when food enterns the stomach

  when food enters the stomach the it simulates the secretion of the hydrochloric acid from the stomach wall. The HCl increases the acidity to about pH2 -- the optimum pH for stomach enzymes.
• what does the hydrochloric acid do in the stomach

  it first attacks any microbes that may have been swallowed when food was eaten. it creates the perfect environment for the protease enzyme
• what do the enzymes then do

  begin digesting the proteins in the swallowed food. the proteins are borken down to release amino acids
• what are the three small soluble molecules that foods are broken down into

  glycerol, amino acids and phosphate
• what is still to be chemically digested

  fats, which happens in the next stage of digestion
• what could cause the lining of the small intestine to be digested

  gastric juices which are very acidic, but bile and mucus can sop this from happening
• when bile and gastric juices meet, what is the result

  neutralisation which is essential for lipase to function properly
• what are the influential organs in the digestion of fat

  liver, gall bladder, pancreas and small intestine
• talk about the breaking down of fats.

  liver produces bile, it is passed down the gall bladder through the bile duct, where it meets the fats in the gastric juice. the bile emulsifies (breaks down) the fats. fat isnt chemically digested which means there is a bigger surface area over which lipase can attack the fat. the pancreas and small intestine then release the enzymes, carbohydrase, proteases and lipases.
• what is a substrate


  a molecule on which the enzyme acts

  
• where is amylase and what does it do

  found in salivary glands, small intestine and pancreas and it breakdown starch into sugar
• where is protease and what does it do

  found in stomach, pancreas and small intestine and it breaks down proteins into amino acids.