bio p1

• What is diffusion


  The movement of particles from an area ofhigh concentration to an area of low concentration.
• What is osmosis


  The movement of water molecules across apartially permeable membranefrom a region of higher water concentration to a region of lower water concentration
• What factors affect diffusion

  The concentration gradient,

  The Temperature,

  Thickness of walls
• What is the nucleus


  Control center of the cell. Contains DNA.
• What is cytoplasm


  Where chemical reactions take place
• What is active transport?


  Movement of a substance against the concentration gradient.Requires energy from respiration
• Do single celled organisms have a small or large surface area to volume ratio

  large
• Do multicellular organisms have a small or large surface area to volume ratio

  Small
• How are leaves adapted for gas exchange?

  Leaves have lots of stomata on the underside to allow carbon dioxide to diffuse
• How are gills adapted for gas exchange?

  gill filaments provide a large SA.

  the lamellae on the filaments increases the SA even more.

  the capillary networks in all the lamellae provides a short diffusion distance.

  .
• How is the small intestine adapted for absorption?

  Villi and microvilli provide a very large surface area.

  The villi are one cell thick- easy for digested food to diffuse into it and absorb it into the blood capillaries

  It has a steep concentration gradient to help with diffusion

  Villi have a good supply of blood
• How are alveoli adapted for gas exchange?

  • large surface area

  • good blood supply

  • thin - short diffusion pathway

  • moist - dissolve gases
• What is a cell


  The basic unit of all living things
• What are tissues


  Groups of cells that are similar in structure and function that work together
• What are organs


  Organs are groups of tissues that work together to perform certain functions
• What is an organ system


  A group of organs working together to perform a particular function
• What are enzymes


  biological catalysts that speed up reactions
• What is the function of digestion

  Digestive enzymes break BIG molecules down into smaller, soluble ones.

  These can pass through the walls of the digestive system and be absorbed into the blood.
• What does amylase do and where is it produced

  - converts starch to maltose

  - Salivary glands, pancreas, small intestine
• What does protease do and where is it produced

  -Breaks down proteins into Amino acids

  -Produced in stomach, pancreas and small intestine,
• What does lipase do and where is it produced

  - fats into fatty acids and glycerol

  - Pancreas and small intestine
• How does bile speed up digestion?

  Emulsifies fats, larger SA for lipase to work on(easier to break down)

  Makes conditionsalkalineso enzymes work better in the small intestine
• What are ribosomes


  site of protein synthesis
• What is the mitochondria?


  where most of the reactions foraerobicrespiration take place
• What is the cell membrane?


  controls what goes in and out of the cell
• What is cell wall

  made of cellulose supports the cell and strengthens it
• What are chloroplasts?


  Membrane-bound organelles where photosynthesis takes place in plants
• What is a permanent vacuole?

  Contains cell sap
• What sub cellular structures do only plant cells have

  Chloroplasts

  Vacuole
• What are prokaryotic cells?


  Cells without a nucleus
• What are eukaryotes?


  cells with a nucleus
• Benefits of electron microscopes

  Higher magnification and resolution

  See more sub cellular structures
• Magnification equation


  magnification = image size/actual size
• What are chromosomes?


  Coiled up lengths of DNA molecules that are found in the nucleus, normally in pairs of body cells
• What is the cell cycle


  A series of stages in which cells divide to produce new cells
• What does a cell do before it divides

  Grow in size

  Increase amount of sub cellular structures

  Duplicate it's dnA
• What is mitosis


  The state of the cell cycle when the cell divides
• What happens during mitosis


  Dnahas beendoubledso there is Two copies of each chromosome in the parent cell

  One set of chromosomes ispulled to each end of the cell

  Cytoplasm and cell membranesdivide

  Two cellsare formed, which areidenticalto each other and to the parent cells
• In what cells does mitosis occur

  body cells
• What is binary fission?

  The simple cell division process by which bacterial cells replicate