b1 key concepts

• the nucleus contains the cells genetic material in the form of DNA
• the ribosomes are where protiens are made in the cell
• the cytoplasm is a jelly-like substance containing the nutrients and salts , where chemical reactions take place
• mitochondria is the sight for aerobic respiration and is where most of the energy is released for the cell to use
• chloroplast is the sight for photosynthesis, where the green pigment chloropyhll absorbs light energy from the sun to make glucose
• The vacoule is a large sac in the middle of the cell which contains a watery solution of sugars and salts (cell sap). it helps maintain the structure of the cell
• the cell wall is made of cellulose. This makes it strong and allows it to maintain its rigid shape.
• Bacteria cells are classed as prokaryotik organisms
• bacteria cells do not contain a nucleus instead they have chromosmal DNA
• the pathway of light through a microscope = light source - stage - microscope slide - object - objective lens - body tube - eyepiece lens - eye
• mm to µm you times by a thousand
• nm to µm you divide by 1000
• cm to µm times by 10000
• magnification = image size divide by object size
• A catalyst is substancer that increases the rate of a reaction without being used up in the reaction
• enzymes are a special type of catalysts. they are large protiens made from long chains of amino acids.
• in order for a enzyme to catalayse a reaction, the active site must be complementary to the substrate
• optimum temprature is when enzyme activity is highest
• enzymes never die they denature when the temp and ph is not optimum
• carbohydrates, lipids and protiens are 3 biological molecules we need in large quantities
• we need carbohydrates to provide energy for chemical reactions.
• fats and oils make up lipids
• we need lipids to insulate us and help regualte our body tempreture and provide energy for chemical reactions
• protiens are important for growth and producing new cells
• calcium is important for strong bones
• scurvy disease is cause by lack of vitamin c
• we need iron in our diet. Iron is an important component of haemoglobin which is the protien in red blood cells that allows for transport of oxygen around the body. a lack of iron can lead to anaemia, where we can transport enough oxygen to our tissues
• we need fibre to help move food through our intestines
• 3 ways to lose water from body is by breathing, sweating and urinating
• we call carbs, proteins and lipids biological molecules and nutrients
• carbohydrates are made up of carbon, hydrogen and oxygen atoms
• many monomers make up a polymer
• amino acids (protien) are made up of carbon, hydrogen, oxygen and nitrogen atoms
• Enzymes in the stomach and small intestine break down food into smaller pieces, protiens into amino acids
• lipids are made up of a single glycerol molecule attached too three fatty acid molecules
• Enzymes in the small intestine are responsible to breaking lipids
• starch is broken down by the enzyme amylase into maltose molecules, these are further broken by maltose into glucose
• protiens are broken down by the enzyme protease into single monomers called amino acids
• pepsin and trypsin are both protease enzymes
• the small intestines and pancreas both produce lipase, which breaks down lipids into fatty acids and glycerol