Biology paper 1- Things im unsure on

• Metabolism

  The combination of all chemical reactions in an organism
• What is glucose converted to during anaerobic respiration in animals?

  lactic acid
• How cells use energy from respiration

  combine small molecules to make larger molecules

  To break large molecules into smaller molecules

  For muscle contraction

  To maintain our body temperature

  To move substances around the cell
• word equation for anaerobic respiration in plants and fungi

  Glucose ➔ ethanol + carbon dioxide
• What are the two reasons animals cells prefer aerobic respiration to anaerobic respiration?

  • Anaerobic respiration doesn't break down the glucose molecule completely,
  • and so releases less energy than aerobic respiration
  • Anaerobic respiration produces lactic acid which can damage cells and leads to an oxygen debt
• word equation for anaerobic respiration in animals

  Glucose> lactic acid + energy
• Which type of respiration leads to the build up of lactic acid, aerobic or anaerobic?

  anaerobic respiration
• Which organ in the body removes the lactic acid from the blood.

  liver
• Name the chamber A on the diagram below

  A

  A)

  
• What does a valve do?

  prevents blood flowing backwards
• Why does the left ventricle have thicker walls?

  to pump blood around the entire body
• Which blood vessel carries deoxygenated blood from the heart to the lungs?

  pulmonary artery
• Journey of blood around the body

  Body tissues ➔ vena cava ➔ right atrium ➔ right ventricle ➔ pulmonary artery ➔ lungs ➔ pulmonary vein ➔ left atrium ➔ left ventricle ➔ aorta ➔ body tissues
• Which blood vessel carries oxygenated blood from the heart to the body?

  Aorta
• The movement of blood between the ventricles and atria: 

  1. The walls of the atria contract, pushing blood into the relaxed ventricles.
  2. The walls of the ventricles contract, pushing blood out of the heart. At the same time, more blood will enter the now-relaxed atria.
  3. The cycle repeats.
• Pacemaker cells are found in which chamber of the heart?

  Right atrium
• Arteries

  carry blood away from the heart
• Veins

  carry blood to the heart
• coronary arteries

  supply the heart muscle with oxygen and nutrients.
• Capillaries

  carry blood through the body tissues, allowing oxygen, nutrients, and waste products, to be exchanged between tissues and the blood.
• Structure and function of arteries

  1. Arteries are large and carry blood at a very high pressure.
  2. Artery walls have a thick middle layer, containing both muscle and elastic tissue.
  3. The muscle tissue provides strength, and allows the arteries to direct blood flow.
  4. The elastic tissue allows the arteries to stretch and recoil.
  5. Compared to their walls, arteries have a relatively narrow lumen, which keeps the blood pressure high.
• Structure and function of capillaries

  1. Capillaries are the smallest of the three blood vessels.
  2. The role of capillaries is to exchange nutrients and waste products with the tissues.
  3. Capillary walls are permeable, meaning substances are able to move through them.
  4. Their walls are also only one cell thick which means a short distance for diffusion.
  5. Capillaries carry blood at a low pressure and have a lower rate of flow than arteries.
• nutrients that are exchanged between the blood in the capillaries and the body tissues

  Glucose and Amino acids
• waste products that are exchanged between the blood in the capillaries, and the body tissues

  Carbon dioxide and urea
• Structure and function of veins

  1. The role of veins is to carry blood from the body (or lungs) back to the heart.
  2. Veins are a similar size to arteries, but they have relatively thin walls and a relatively small lumen
  3. This is because they carry blood at a much lower pressure.
  4. Veins also contain valves to prevent the blood from flowing backwards.
• tumour

  abnormal mass of cells that forms when a group of cells undergo uncontrolled growth and division
• Which cancer does BRCA increase the risk of?

  ovarian cancer + breast cancer
• The upper epidermis is transparent so that light can pass through it. This means that as much light as possible can reach the palisade mesophyll cells below, and be used in photosynthesis. 
• Plant cell organisation- Which structures help to minimise water loss?

  cuticle and stomata
• If there is plenty of water in the leaf, guard cells become turgid, which opens the stomata. This allows carbon dioxide to enter the leaf, but also allows water to escape. 
• What is meristem tissue and where is it found? 

  Meristem tissue is made up of plant stems cells. It's found in the growing parts of the plant such as the tips of shoots and roots. 
• What do we call the movement of cell sap (a mixture of sugar and water) up and down the plant?

  translocation
• Phloem cells have _________ in their end walls to allow cell sap to pass along the phloem tube.

  pores
• What does the xylem transport in a plant?

  water + dissolved mineral ions
• How do root hair cells absorb mineral ions from the soil?

  active transport
• Which substance are xylem cells reinforced with to make them stronger? 

  lignin
• Why does the rate of transpiration increase if the light intensity is increased?

  The stomata open wider to let more carbon dioxide into the leaf for photosynthesis.
• What is the movement of sugars throughout a plant called?

  translocation
• Water passes up the plant via the:

  xylem
• Translocation takes place via phloem tubes. These are made up of lots of phloem cells, which are separated by tiny pores that allow cell sap to pass through.