Cell Structures and their functions

Cell Surface Membrane

• To protect the cell from its surrounding.
• Control changes between cell and the environment

Nucleus

• It's a center control cell
• Control cell growth and reproduction

Nuclear envelope

• Has many small pores called nuclear pores to allow and control exchange between nucleus and cytoplasm
• → Leaving = RNA & ribosomes for protein synthesis
• → Entering = Protein(help ribosomes making), ATP(aderosine                        triphosphate) , also thyroidhormone T3.

Nucleolus

• Primary function to assemble ribosomes,
• Makes proteins and ribosomal RNA (rRNA) and send it to the cell to form ribosomes

Rough endoplasmic reticulum

• Is a series of connected flattened sacs that have many ribosomes on their outer surface, which is responsible to process many proteins.

Smooth endoplasmic reticulum

• Makes lipid and steroids.
• e.g cholesterol and the reproductive hormones like oestrogen and testosterone.

Golgi body (Golgi apparatus or Golgi complex)

• To collect, process, and sort molecules(mostly protein from rough ER), ready for transport either to other part of cell or export out of the cell(do secretion).

Mitochondria (including small circular DNA)

• Responsible to carry out aerobic respiration to make ATP(Adenosine Triphosphate), High energy storage that stores every energy that we need to do our activities.
• DNA and ribosomes are responsible for coding and synthesis of certain vital proteins.

Ribosomes (80S in the cytoplasm and 70S in chloroplasts and mitochondria)

• The one who makes Protein, which is responsible for repairing cell damage and directing chemical processes

Lysosomes

• Hold enzymes that first created in the rough endoplasmic reticulum, then packaged by Golgi apparatus resulting Lysosomes.
• To digest and breakdown all types of biological polymers like proteins, nucleic acids, carbohydrates, and lipids, when they die.

Centrioles

• Centrioles replicate during the interphase stage of mitosis and meiosis.
• Help the movement of ciliogenesis (simply the formation of cilia and flagella on the surface of t=cells, which cilia and flagella help the cell move.)

Microtubules 

• Filamentous intracellular structures that are responsible for movements in all eukaryotic cells.
• In non-dividing cells, micro-tubule networks radiate out from the centrosome to provide the basic organisation of the cytoplasm & positioning of organelles
• To produce messenger RNA, followed by the translation of mRNA by the ribosomes on order to produce protein.
• Maintain allpha and beta tubulin to form heterodimer (protein consists of 2 different gene products)
• Assembly and disassembly within the cell to determine cell movements (forms of cell locomotion, the intracellular transport of organelles, and the separation of chromosomes during mitosis

Chloroplasts (including small circular DNA)

• Tiny energy factories from the sun
• It's helping the process of photosynthesis using chlorophyll by converting the sun's energy into storage form in ordered sugar molecules such as glucose.
• Thylakoids in choloroplasts looks like stacks of discs or coins called grana that are connected to an extensive system of tubules, they act to trap the energy from sunlight.

Cell wall

• Protects against pathogens, dehydration, and other environmental factors, support, control, maintain, signals, interact, form and protect the organisms.
• Able to dissolve in water and able to form long chains to support plants
• Regulate diffusion of material through the apoplast
• Prevents water loss, helps the osmotic regulation
• Diffusion of gases in and out of the cell.

Plasmodesmata

• It’s a fine strands of cytoplasm.
• Channels through cell walls to allow molecules and substance move back and forth as needed.

Large permanent vacuole

• A mature plant cells, surrounded by tonoplast.
• Process and hold materials and wastes, maintain proper pressure in plant cells to provide structure and support growing plants.

• Pigments of plant colours

Tonoplast of plant cells

• Also called as ‘vacuolar membrane’. Usually filled with foods, and/or wastes particles.
• Controls exchange between vacuoles and cytoplasm.