01 Organelles
Cytoplasm
Cytosol + Organelles
Ribosome -function
assembles proteins from amino acids.
Proteins produced on the ER ribosomes are destined either for:
(a) secretion from the cell, such as occurs with peptide hormones like insulin and glucagon (b) packaging into cytoplasmic organelles, such as lysosomes and peroxisomes (c) embedding in the plasma membrane or organelle membranes, for example channel proteins
Smooth endoplasmic reticulum -function
(a) the production of phospholipids for cell membranes (b) synthesis of steroid hormones
Secretory Vesicles
Cell secretions - e.g. hormones, neurotransmitters - are packaged in secretory vesicles at the Golgi apparatus. The secretory vesicles are then transported to the cell surface for release.
Cell Membrane -Structure
It is made from two layers of phospholipid molecules, called a phospholipid bilayer.
Lysosome
Lysosomes contain digestive enzymes. Breaks down foreign material.
Mitochondrion -structure
Mitochondria are membrane bound organelles with a smooth outer membrane and a convoluted inner membrane.
Cell Wall
Protective barrier that maintains the shape of the cell. In plants it is made of cellulose (a polysaccharide). In bacteria it is made of peptidoglycans, in fungi it is made of chitin.
Membrane Proteins
Proteins are embedded in the membrane; some only penetrate part of the way through the membrane. Some span the whole membrane. Some form pores or channels for other molecules to move across the membrane.
Peroxisome
Rids the body of toxic substances. Important in the liver and kidneys which are the main sites of detoxification.
Rough Endoplasmic Reticulum -structure
Rough endoplasmic reticulum (rough ER) is a network of folded membranes with attached ribosomes.
Chloroplast
Site of photosynthesis in plants, contain the chemical chlorophyll.
Rough Endoplasmic Reticulum -Function
Synthesis, folding, and modification of proteins. Transport of proteins through the cell. Membrane production.
Golgi Body -structure
The Golgi Apparatus, also called the Golgi Bodies or Golgi Complex, is a system of folded membranes and vesicles in eukaryotic cells.
Cytoskeleton -structure
The cytoskeleton is a network of protein fibres throughout cells. The cytoskeleton of eukaryotic cells includes microtubules, actin microfilaments and intermediate filaments.
Cytoskeleton -function
The cytoskeleton is like an inner scaffold providing structure for the cell. The microtubles and filaments also create tracks for organelles to travel around the cell. The protein fibres can slide over each other, allowing the whole cell to move.
Cell Membrane
The membrane defines the boundary of the cell and controls what enters and leaves the cell
Mitochondrion -function
The mitochondrion is an organelle for aerobic cellular respiration, generating ATP (chemical energy).
Nuclear Membrane
The nuclear membrane, or nuclear envelope, is a double lipid bilayer containing pores through which molecules can enter or exit the nucleus.
Nucleolus
The nucleolus is where ribosomes are built from RNA and proteins. Ribosomes are a structure that travel from the nucleus to the cytoplasm through the nuclear pores.
Nucleus
The nucleus of the cell carries the genetic material, the DNA. Responsible for regulating all the activities of the cell.
Smooth Endoplasmic Reticulum- Structure
The smooth endoplasmic reticulum (smooth ER) is a network of membranes in the cytoplasm resembling the rough ER but without ribosomes.
Golgi body -function
This is where proteins are sorted and packaged into vesicles for delivery to the plasma membrane for secretion (release from the cell) or to other locations within the cell, such as lysosomes and peroxisomes. Modification of proteins and lipids received from the ER. Sorting, packaging, and storage of proteins and lipids.
Vacuole
Vacuoles and vesicles are both membrane-bound sacs, but vacuoles are larger. Plant cells have a large vacuole that is involved in the storage of water and wastes.
Smooth endoplasmic reticulum is abundant in
cells that produce steroid hormones. For example cells in the ovaries making estrogen
Golgi apparatus is abundant in
cells that secrete proteins, such as endocrine glands. For example, cells in the pituitary gland produce peptide hormones like growth hormone which are released into the blood stream.
Cytosol
fluid contents of the cell
Ribosome -Structure
made of rRNA and protein. Not membrane bound. They are found 'free' in the cytoplasm or attached to endoplasmic reticulum membranes (rough endoplasmic reticulum).