2.3 living processes in multicellular organisms (p2)

mitochondrion

type of cell	function
sperm cell	requires a lot of energy to swim towards the uterus and fallopian tube to fertilise the secondary oocytes
muscle cell	requires a lot of energy to contract and relax to produce movement
meristem cells in shoot and root tips	requires a lot of energy to carry out active cell division process to produce new cells

chloroplast

type of cell	function
palisade mesophyll cell	has many chloroplast which contain chlorophyll to absorb energy from sunlight for photosynthesis
spongy mesophyll cell	has lesser chloroplasts compared to palisade mesophyll cell to carry out photosynthesis
guard cell	carries out photosynthesis

rough endoplasmic reticulum and golgi apparatus

type of cell	function
pancreatic cell	requires rough endoplasmic reticulum to transport the protein synthesised by ribosomes to the golgi apparatus, to modify the proteins into specific secretions such as enzymes and hormones
goblet cell in intestinal epithelium and respiratory tract	helps digestion of food in alimentary canal and secretes mucus to trap dust + microorganisms in the respiratory tract

smooth endoplasmic reticulum and golgi apparatus

type of cell	function
liver cell	metabolises carbohydrates synthesises lipids detoxifies drugs and toxins

if there is an absence, failure or lack of an organelle in a cell, then….

the cell cannot function effectively. this will effect the survival of the organism.

absence of : lysosomes

it contains hydrolytic enzymes to break down organic compounds in the cell and to break down components of a damaged cell

• in its absence, these substances cannot be broken down and will build up in a cell and become toxic. this will damage cells and organs in the body.

absence of : mitochondrion

carries out aerobic respiration to release energy

• in its absence, respiration cannot occur, so there is no energy for the cell to carry out its activity. this will lead to the death of the organism.

absence of : chloroplast

chlorophyll is required to absorb energy from sunlight for photosynthesis

• in its absence, the plant cannot carry out photosynthesis. the plant will die

• if mesophyll cell lacks chloroplasts, the rate of photosynthesis will decrease. less food is synthesised and this will affect the growth of the plant.

absence of : ribosomes

• in the absence of ribosomes, protein is not synthesised. the cell will not be able to repair cellular damage, produce hormones and maintain cellular structure

tay-sachs disease

• a rare genetic disorder caused by the failure of lysosomes to produce an enzyme that breaks down certain fatty substances

• these fatty substances will build up to toxic levels in the patient’s brain and affect the function of nerve cells

• as the disease progresses, the child loses muscle control. eventually, this leads to blindness, paralysis and death.

mitochondrial dysfunction

• occurs when the mitochondria cannot function properly

• there is less cellular respiration, less energy released

• this will result in excessive fatigue, muscle weakness and other symptoms as such in other chronic diseases.