Cell Structure and Organelles

Cell Structure

• Plasma Membrane: semi-permeable membrane that separates the cell from its environment
• Cytoplasm: jelly-like substance inside the cell membrane where metabolic processes take place
• Nucleus: control center of the cell where DNA is stored
• Mitochondria: organelles responsible for generating energy for the cell
• Endoplasmic Reticulum (ER): network of membranous tubules and cisternae involved in protein synthesis and transport
• Ribosomes: site of protein synthesis
• Lysosomes: membrane-bound sacs that contain digestive enzymes
• Cytoskeleton: network of filaments that provides structural support and shape to the cell

Cell Types

• Prokaryotic Cells: lack a true nucleus, found in bacteria
• Eukaryotic Cells: have a true nucleus, found in plants, animals, fungi, and protists
• Stem Cells: undifferentiated cells that can differentiate into specialized cells
• Differentiated Cells: specialized cells that perform specific functions (e.g. nerve cells, muscle cells)

Tissue Types

• Epithelial Tissue: forms the lining of organs and glands, protects underlying tissues
• Connective Tissue: provides support and structure to the body, includes bone, cartilage, and fat
• Muscle Tissue: responsible for movement and contraction
• Nervous Tissue: transmits and processes information, includes brain, spinal cord, and nerves

Tissue Functions

• Protection: epithelial tissue protects underlying tissues, connective tissue provides structural support
• Support: connective tissue provides framework for the body
• Movement: muscle tissue allows for movement and contraction
• Regulation: nervous tissue regulates body functions and responds to stimuli

Cell Structure

• The plasma membrane is a semi-permeable membrane that separates the cell from its environment and regulates the movement of substances in and out of the cell.
• Cytoplasm is a jelly-like substance inside the cell membrane where metabolic processes, such as protein synthesis and cell signaling, take place.
• The nucleus is the control center of the cell where DNA is stored, and it plays a crucial role in regulating cell growth and reproduction.
• Mitochondria are organelles responsible for generating energy for the cell through cellular respiration, producing ATP from glucose and other organic molecules.
• The endoplasmic reticulum (ER) is a network of membranous tubules and cisternae involved in protein synthesis, lipid synthesis, and detoxification.
• Ribosomes are the site of protein synthesis, where messenger RNA (mRNA) is translated into a specific sequence of amino acids.
• Lysosomes are membrane-bound sacs that contain digestive enzymes, which break down and recycle cellular waste and foreign substances.
• The cytoskeleton is a network of filaments that provides structural support and shape to the cell, and plays a role in cell division, movement, and signaling.

Cell Types

• Prokaryotic cells lack a true nucleus, have a single circular chromosome, and are typically found in bacteria, such as E. coli.
• Eukaryotic cells have a true nucleus, linear chromosomes, and are found in plants, animals, fungi, and protists, such as yeast and paramecia.
• Stem cells are undifferentiated cells that can differentiate into specialized cells, such as nerve cells, muscle cells, or blood cells, through the process of cell differentiation.
• Differentiated cells are specialized cells that perform specific functions, such as transmission of nerve impulses, contraction of muscles, or production of hormones.

Tissue Types

• Epithelial tissue forms the lining of organs and glands, and protects underlying tissues from damage, infection, or desiccation.
• Connective tissue provides support and structure to the body, and includes bone, cartilage, fat, and blood, which support various bodily functions.
• Muscle tissue is responsible for movement and contraction, and includes skeletal, smooth, and cardiac muscle, which work together to maintain posture, move limbs, and pump blood.
• Nervous tissue transmits and processes information, and includes the brain, spinal cord, and nerves, which are responsible for controlling various bodily functions.

Tissue Functions

• Protection is provided by epithelial tissue, which forms a barrier against external damage, and connective tissue, which provides structural support to the body.
• Support is provided by connective tissue, which forms the framework of the body, and muscle tissue, which maintains posture and movement.
• Movement is facilitated by muscle tissue, which allows for contraction and relaxation of muscles.
• Regulation is performed by nervous tissue, which regulates body functions, responds to stimuli, and integrates information from various sensory inputs.