4.1-4.13 plant structure and function

amyloplasts

organelles found in the cytoplasm of plant cells that are used to store amylopectin, a form of starch

calcium ion

a type of ion that is found in the middle lamella of plant cells, it combines with pectin to form calcium pectate, which holds plant cells together

captive breeding programme

breeding wild animals in a safe environment like a zoo or sanctuary to increase population size

cell vacuole

a membrane bound structure found in plant cells that contains cell sap

cell wall

a permeable layer that surrounds plant, algae and fungi cells made of polysaccharides which provides strength to the cell

cellulose

a polysaccharide made of beta glucose monomers joined by beta 1,4 bonds that is used as a structural polysaccharide which provides strength to plant cell wall

chloroplast

an organelle found in plants and algae that is the site of photosynthesis

cross linking

a phenomenon which allows chains of beta glucose monomers in cellulose to be held firmly together through hydrogen bonding between the partially positively charged hydrogen atoms of the hydroxyl (-OH) group and the partially negatively charged oxygen atoms in other areas of the glucose molecules

double blind trail

a drug trial in completed where neither the researcher or patient know which drug is a placebo and which is the working drug in order to remove researcher bias

magnesium ion

a type of ion with the formula Mg2+ which is needed for chlorophyll to function so that plants can carry out photosynthesis

mcirofibrils

fibrils made of cellulose that largely compose plant cell walls they are laid down in layers held together by a matrix of hemicelluloses and other short chain carbohydrates

middle lamella

a layer made up of pectins which joins the cell walls of adjacent plant cells together

mitochondrion

an organelle found in eukaryotic cells that is the site of aerobic respiration

nitrate ion

a type of ion with the formula NO-3 which is taken up by plants from the soil and is used to make proteins

phase 1 clinical trail

a clinical trail where the drug is tested on a small group of healthy volunteers to test for safety and side effects

phase 2 clinical trail

a clinical trail where the drug is tested on a small group of patients suffering from the disease to determine how effective the drug is and what the most appropriate dose is

phase 3 clinical trail

the final phase in clinical trails where the drug is tested to observe its effects in a much larger group of patients

phloem sieve tubes

living phloem cells joined together to create a long tube for the efficient transport of assimilates

phloem

a tissue found in plants which is specialised for the transport of assimilates from their site of production to different parts of the plant where they are needed

phosphate ion

a type of ion needed for the phosphate groups in ADP and ATP which are involved in energy transfer

pits

thin sections of the cell wall that allow for the exchange of water and minerals between adjacent cells

placebo

a replica of the drug being tested that is indistinguishable from the real drug yet it exerts no effects on the patient whatsoever

plasmadesmata

cytoplasmic bridges between adjacent plant cells that allow the transport of molecules between the cells

primary cell wall

the primary cell wall is made of cellulose microfibrils oriented in a similar direction

reintroduction programmes

releasing animals from captivity back into the wind in a controlled and safe manner

sclerenchyma

plant tissue made up of cells with thickened cell walls which is used for strength and support

secondary cell wall

made of cellulose microfibrils oriented at different angles to one another, which make the composite material more rigid, hemicelluloses harden this material further

tonoplast membrane

the membrane which surrounds the cell vacuole

ultrastructure

the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope

william withering’s digitalis soup

one of the first examples of drug testing where the correct dose of digitalis from the poisonous foxglove plant to treat heart disease was determined by william withering

xylem

a tissue found in plants which is specialised for the transport of water and dissolved minerals up the plant