bio

• plant cell


  nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole
• animal cell


  nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
• function of nucleus


  Controls the activity of the cell (by making proteins)

  Contains the chromosomes - strands of DNA which carry the genes.
• function of cytoplasm


  Where metabolic chemical reactions take place
• function of cell membrane


  controls what enters and leaves the cell
• function of mitochondria


  site of aerobic respiration to produce ATP
• function of ribosomes


  site of protein synthesis

  protein from amino acids
• function of cell wall

  give cell shape and strength
• function of vacuole


  contains cell sap and stores dissolved sugars mineral ions for the plant
• function of chloroplasts


  contains green pigment needed for photosynthesis
• similarities between plant and animal cells

  Both cells have ribosomes, cytoplasm, mitochondria, nucleus, cell membrane, vacuole and both eurkaytic cells
• differences between plant and animal cells

  plant cells have chloroplasts, a cell wall, and vacuoles while animal cells do not.
• what does nucleus contain

  chromosomes made of DNA - genes
• chemical elements present in carbohydrates

  Carbon, hydrogen, oxygen
• chemical elements present in proteins

  carbon, hydrogen, oxygen, nitrogen
• chemical elements present in lipids


  carbon, hydrogen, oxygen
• describe the structure of carbohydrates as large molecules made up from smaller basic units

  starch and glycogen from simple sugars
• describe the structure of proteins as large molecules made up from smaller basic units

  protein from amino acids
• describe the structure of lipids as large molecules made up from smaller basic units


  lipid from fatty acids and glycerol
• magnification


  I/am
• level of organisation


  organelle, cell, tissue, organ, organ system, organism
• organelle


  A tiny cell structure that carries out a specific function within the cell
• cell


  Cells are the smallest functional unit of life and contain a number of organelles, structures that carry out specific processes the cells needs to survive.
• tissue


  Tissues are groups of similar cells, which work together to carry out the same function (job). An example in humans is muscle tissue.
• organs


  Organs are made up of several different tissues working together to carry out a more complex function. In humans, muscle is one of the tissues making up the heart.
• organ system


  Organ systems are made up of several different organs working together to carry out a complex function essential to life (e.g. circulating blood around the body).
• stem cells


  All cells begin as stem cells - these are not specialised to a particular job, but are able to divide over and over to make new cells.

  Some stem cells then differentiate (develop new features) to become specialised cells - ones which have the structures and proteins needed to carry out a specific job in the organism.
• RBC


  Function: to transport oxygen in the blood Features:

  Contains the protein haemoglobin - binds to and transports oxygen

  No nucleus - more space for haemoglobin

  Biconcave shaped (pinched disc) - larger surface area, so oxygen can enter and leave the cell more rapidly
• sperm cell


  Function: to transport male genetic material to the egg cell

  Features:

  Flagellum (tail) - to allow the sperm cell to swim

  Many mitochondria - to provide the energy needed for swimming

  Acrosome - package of enzymes, to digest the jelly layer surrounding the egg cell
• Palisade (leaf) cell


  Function: to carry out photosynthesis Features:

  • Many chloroplasts - trap light energy for photosynthesis

  • Tall and thin - cells can pack tightly together so more of the light reaching the leaf is absorbed
• the genome


  entire DNA of an organism and that a gene is a section of a molecule of DNA that codes for a specific protein
• DNA molecule


  two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thymine (T), and cytosine (C) with guanine (G)
• Carbohydrate


  Carbohydrates are broken down in a chemical reaction, respiration, to release energy in the form of

  ATP. This energy is used for other reactions and processes in cells.

  Simple sugars (e.g. glucose and fructose) are the smallest units of carbohydrates.

  Two sugar molecules can be joined together, e.g. glucose + fructose makes sucrose.

  Many sugar molecules are joined together to make complex carbohydrates
• Carbohydrate elements


  carbon, hydrogen, oxygen
• Complex carbohydrates and their uses

  Starch - used to store glucose in plants

  Glycogen - used to store glucose in animals and fungi

  
  

  Starch and glycogen are better storage molecules as they are insoluble than simple sugars and so have less effect on water movement in and out of cells.

  
• Lipids (fats) and functions


  Made of 3 fatty acids joined to a glycerol molecule

  Many functions:

  Energy storage (can also be used in respiration

  Part of cell membranes

  Thermal insulation

  Electrical insulation - around nerve cells

  
• Lipids elements


  Carbon, hydrogen, oxygen
• Protein


  Made of many amino acids joined together

  There are 20 different amino acids which can be combined in any order, resulting in millions of

  different protein structures

  Lots of functions in the body:

  - Structural molecules (e.g.

  collagen and keratin)

  - Controlling chemical reactions -

  these are enzymes;

  - Transport - e.g. haemoglobin and

  cell membrane proteins
• Protein elements


  Made of carbon, hydrogen, oxygen and nitrogen.
• food test for glucose (sugars)

  Benedict's Solution- test for reducing sugars (glucose)

  Add Benedict's solution to a sample of food (in solution)

  Place in a water bath at 80oC for 5 minutes.

  If a reducing sugar is present the colour will change from blue to brick red. If it is green, yellow, or orange it is still a positive result but will have a lower concentration of the sugar.

  BLUE TO RED/YELLOW/GREEN