Eukaryotic Cell Summary PDF

**What are eukaryotic cells?** Eukaryotic cells are complex, membrane-bound structures that contain specialized organelles responsible for various cellular functions. These cells are characteristic of plants, animals, fungi. They are larger and more organized than prokaryotic cells. Compartmentaliz...

**What are eukaryotic cells?** Eukaryotic cells are complex, membrane-bound structures that contain specialized organelles responsible for various cellular functions. These cells are characteristic of plants, animals, fungi. They are larger and more organized than prokaryotic cells. Compartmentalization allows for efficient cellular processes, such as energy production, protein synthesis, and waste management, making eukaryotic cells more complex than prokaryotic cells *[Structure ]* - *Plasma membrane* The plasma membrane is a lipid bilayer that encloses the cell, composed mainly of phospholipids, cholesterol, and proteins. It functions as a selective barrier, regulating the transport of molecules in and out of the cell. Integral and peripheral proteins embedded in the membrane assist in signaling, transport, and structural support - *Membrane bound nucleus* The nucleus is the control center of the cell, containing the genetic material (DNA) organized into chromosomes. It is surrounded by a **nuclear envelope**, a double membrane with nuclear pores that regulate the exchange of materials between the nucleus and cytoplasm **Nucleolus**: A dense region within the nucleus where ribosomal RNA (rRNA) is synthesized and ribosome assembly begins - *Cytoplasm* The cytoplasm is the jelly-like substance filling the cell, consisting of cytosol (fluid), organelles, and the cytoskeleton. It provides a medium for biochemical reactions and allows organelles to be suspended and positioned - *Endomembrane system* *This system includes several interconnected organelles that work together for the synthesis, processing, and transport of proteins and lipids* - Consists of : R/S ER, Golgi apparatus, vesicles and vacuoles - *Cytoskeleton* The cytoskeleton provides structural support and facilitates movement within the cell. It is composed of three main types of protein filaments: - Microfilaments (Actin(protein) Filaments): Involved in cell movement and shape changes, including muscle contraction. - Intermediate Filaments (made from variety proteins): Provide mechanical strength to the cell. - Microtubules: Hollow, small tubes made of tubulin that form structures like the mitotic spindle and cilia/flagella and serve as tracks for motor proteins, also helps in cell division. - *Extracellular structures* - Cell wall ( Plant Cells, Fungi, Some Protists): The cell wall is a rigid layer outside the plasma membrane, providing structural support and protection. In plants, it is made primarily of cellulose - Extra-cellular martrix (ECM) (animal cells): The extracellular matrix is a network of proteins and polysaccharides outside animal cells that provides structural support, facilitates cell communication, and helps in tissue organization. - Cilia and flagella *[Main components ]* Eukaryotic Cells \| Boundless Biology \| Study Guides **The common cel organelles** *[Name and Functions ]* +-----------------------------------+-----------------------------------+ | Cel organelle | Function | +===================================+===================================+ | Nucleus | - Structure: Surrounded by a | | | double membrane known as the | | | nuclear envelope, which | | | contains pores to regulate | | | material exchange between the | | | nucleus and cytoplasm. | | | Inside, it contains chromatin | | | (DNA and proteins) and the | | | nucleolus. | | | | | | - Function: | | | | | | The **nucleus** is the control | | | center of the cell, containing | | | the cell's genetic material (DNA) | | | organized as chromatin or | | | chromosomes. | | | | | | **Gene expression**: DNA is | | | transcribed into RNA, which then | | | leaves the nucleus to be | | | translated into proteins in the | | | cytoplasm. | | | | | | **Nucleolus**: Synthesizes | | | ribosomal RNA (rRNA) and | | | assembles ribosomal subunits | +-----------------------------------+-----------------------------------+ | Ribosomes | - Structure: Consist of two | | | subunits (large and small), | | | made up of rRNA and proteins. | | | They can be found free in the | | | cytoplasm or attached to the | | | rough ER | | | | | | - Functions: **Protein | | | synthesis**: Ribosomes are | | | the sites where mRNA is | | | translated into polypeptides | | | (proteins). Free ribosomes | | | produce proteins that | | | function within the cytosol, | | | while ribosomes on the rough | | | ER synthesize proteins for | | | secretion or membrane | | | insertion | +-----------------------------------+-----------------------------------+ | Endoplasmic reticulum | - Structure: A network of | | | membrane-bound tubules and | | | sacs called cisternae. It is | | | divided into two regions: | | | rough (with ribosomes) and | | | smooth (without ribosomes) | | | | | | - Functions: **Rough ER**: | | | Synthesizes proteins that are | | | either secreted from the | | | cell, embedded in membranes, | | | or sent to organelles such as | | | lysosomes. | | | | | | **Smooth ER**: Synthesizes lipids | | | (phospholipids, steroids), | | | detoxifies drugs and poisons | | | (especially in liver cells), | | | stores calcium ions (important | | | for muscle cells), and | | | metabolizes carbohydrates | +-----------------------------------+-----------------------------------+ | Golgi apparatus | - Structure: A series of | | | flattened membrane-bound sacs | | | (cisternae). It has distinct | | | [cis (receiving) and trans | | | (shipping) faces] | | | | | | - Functions: **Protein | | | modification and sorting**: | | | Receives proteins and lipids | | | from the ER, modifies them | | | (e.g., glycosylation), sorts, | | | and packages them into | | | vesicles for transport to | | | their final destinations | | | (cell membrane, lysosomes, | | | secretion). | +-----------------------------------+-----------------------------------+ | Lysosomes | - Structure: Membrane-bound | | | vesicles containing | | | hydrolytic enzymes (only work | | | in pH of 5) | | | | | | - Functions: **Intracellular | | | digestion**: Lysosomes break | | | down macromolecules | | | (proteins, lipids, nucleic | | | acids, carbohydrates) via | | | hydrolytic enzymes. | | | | | | **Autophagy**: Lysosomes digest | | | damaged organelles and recycle | | | their components. | | | | | | **Phagocytosis**: In some cells | | | (like macrophages), lysosomes | | | digest foreign particles or | | | pathogens engulfed by the cell | +-----------------------------------+-----------------------------------+ | Peroxisomes | - Structure: Small, | | | membrane-bound organelles | | | containing enzymes like | | | oxidase and catalase(breaks | | | down fatty acids) | | | | | | - Functions: | | | **Detoxification**: Break | | | down toxic substances, | | | radicals are produced there, | | | particularly hydrogen | | | peroxide (H₂O₂), into water | | | and oxygen via catalase. | +-----------------------------------+-----------------------------------+ | Mitochondria | - Structure: Double-membraned | | | organelles, with an outer | | | membrane and a highly folded | | | inner membrane (forming | | | cristae). The inner space is | | | called the matrix, which | | | contains mitochondrial DNA | | | and ribosomes. | | | | | | - Cells who need more ATP | | | contain more cristae | | | | | | - Functions: **Energy | | | production**: Mitochondria | | | generate ATP through | | | oxidative phosphorylation, | | | which occurs along the inner | | | membrane\'s cristae, as part | | | of the electron transport | | | chain and chemiosmosis. | | | | | | Mitochondria have their **own DNA | | | and ribosomes**, supporting the | | | endosymbiotic theory of their | | | origin, also self-replicating | +-----------------------------------+-----------------------------------+ | Chloroplasts (plant cells) | - Structure: Double-membraned | | | organelles containing | | | thylakoids (flattened sacs) | | | arranged in stacks called | | | grana, surrounded by the | | | fluid-filled stroma. They | | | contain chlorophyll, the | | | pigment necessary for | | | capturing light energy | | | | | | - Functions: | | | **Photosynthesis**: | | | Chloroplasts convert light | | | energy into chemical energy | | | stored in glucose through the | | | light-dependent and | | | light-independent (Calvin | | | cycle) reactions. | +-----------------------------------+-----------------------------------+ | Vacuoles | - Structure: Large, | | | membrane-bound sacs. | | | Particularly large in plant | | | cells, where they occupy most | | | of the cell's volume | | | | | | - Functions: **Storage**: | | | Vacuoles store nutrients, | | | ions, waste products, and | | | pigments. | | | | | | **Digestion**: In some cells, | | | vacuoles may contain hydrolytic | | | enzymes for digestion | +-----------------------------------+-----------------------------------+ | Centrosomes and centrioles | - Structure: The centrosome is | | | a region near the nucleus | | | that contains a pair of | | | centrioles, each composed of | | | microtubules arranged in a | | | 9+0 pattern | | | | | | - Functions: **Microtubule | | | organization**: The | | | centrosome is the main | | | microtubule-organizing center | | | (MTOC), crucial for spindle | | | formation during cell | | | division. | +-----------------------------------+-----------------------------------+ **Differences between eukaryotic and prokaryotic cells** **(main components, structures, organelles,...)**  Prokaryotic and Eukaryotic Cells: Structure and Discrete Features  Afbeelding met tekst, schermopname, Lettertype, nummer Automatisch gegenereerde beschrijving