Paper 1 Key Words

• Aerobic respiration

  Glucose + Oxygen -> Carbon Dioxide + Water
• Amylase

  An enzyme that breaks down carbohydrates into simple sugars
• Anaerobic respiration

  Glucose -> Lactic Acid
• Cellular respiration

  A continuously occurring chemical process which occurs in all living cells. It is exothermic and releases energy in the form of ATP from the breakdown of organic compounds such as glucose
• Limiting factor

  A factor that when in short or inadequate supply limits the rate of a reaction
• Lipase

  An enzyme that breaks down lipids into fatty acids and glycerol
• Lipid

  A large molecule that is synthesised from three fatty acids and a glycerol molecule
• Palisade mesophyll

  A specialised plant tissue that carries out photosynthesis
• Photosynthesis

  Carbon Dioxide + Water -> Glucose + Oxygen
• SEM

  A microscope that uses reflected electrons to produce an image of a specimen. It creates a 3D image with a lower resolution
• TEM

  A microscope that uses transmitted electrons to produce an image of a specimen. It creates a 2D image with a higher resolution so details of organelles can be seen
• Active transport

  The movement of particles from an area of low concentration to an area of high concentration, against the concentration gradient

  This requires energy
• Alveoli

  Small air sacs in the lungs that serve as the gaseous exchange surface. They provide a large surface area for efficient exchange
• Aorta

  The main artery that takes oxygenated blood away from the heart to the body
• Artery

  A blood vessel that carries blood away from the heart under high pressure
• Atrium

  The upper chamber of the heart that receives the blood from the veins
• Cytokinesis

  The third stage of the cell cycle in which two identical diploid daughter cells are formed
• Diffusion

  The net movement of particles from a high concentration to a low concentration
• Embryonic stem cell

  A type of stem cell found in very early embryos that can differentiate into any cell type
• Hypertonic 


  The net movement of water out of the cell via osmosis
• Hypotonic

  The net movement of water into the cell via osmosis
• Interphase

  The first stage of the cell cycle where the cell grows, new proteins are synthesised and chromosomes are replicated
• Lignin

  A material that lines the xylem vessels and provides strength and support
• Meristematic cell

  A type of cell that can differentiate into any plant cell type
• Meristem tissue

  A plant tissue that contains many undifferentiated cells
• Osmosis

  The net movement of water molecules from a region of high concentration to a region of low concentration through a partially permeable membrane
• Phloem

  A plant tissue that transports sugar from the source to the sink
• Pulmonary artery

  The main artery that carries deoxygenated blood away from the heart to the lungs
• Pulmonary vein

  The main vein that carries oxygenated blood back to the heart from the lungs
• Root hair cells

  Specialised cells that provide a large surface area for the uptake of water and minerals from the soil
• Stomata

  Small pores in the epidermis of the leaves that facilitate gaseous exchange
• Translocation

  The process of transporting sucrose around the plant
• Transpiration

  The loss of water from the surface of the leaves by evaporation from the open stomata
• Turgid

  When the vacuole of a plant cells becomes swollen and enlarged with water
• Valves

  Structures found at each end of both ventricles that prevent the backflow of blood
• Vein

  A blood vessel that carries deoxygenated blood to the heart at low pressure
• Vena cava

  The main vein that carries deoxygenated blood back to the heart from the body
• Ventricles

  The lower chambers of the heart that receive blood from the atria and pump it to the arteries
• Villi

  Small projections from the small intestine that increase the surface area for food absorption
• Xylem

  A specialised plant tissue that transports water and dissolved minerals from the roots to the leaves of the plant