The Cell Theory Chapter 2

The Cell All living things are made of cells. Cells are the smallest living unit of life. Each cell performs the necessary functions to sustain life. Cells can replicate themselves. Cancer occurs when cells replicate haphazzardly. Cellular function is carried out by organelles.

Cellular reactions are mediated (controlled) by ENZYMES. Cellular reactions are mediated (controlled) by ENZYMES. Enzymes speed up chemical reactions. Enzymes speed up chemical reactions. All the chemical reactions in the body make up its METABOLISM. All the chemical reactions in the body make up its METABOLISM. There are 10 organelles that you are responsible for. There are 10 organelles that you are responsible for.

Plasma Membrane Outer covering of the cell. Outer covering of the cell. Also called the PLASMALEMMA. Also called the PLASMALEMMA. Separates the intracellular (inside) fluid and the extracellular (outside) fluid. Separates the intracellular (inside) fluid and the extracellular (outside) fluid. Double layer of lipids (fat) with protein molecules between the layers. Double layer of lipids (fat) with protein molecules between the layers.

Polar Head (like water) Polar Head (like water) Non-polar tails (do not like water) Non-polar tails (do not like water) Proteins within the membrane. They give support to the membrane and prevent it from collapsing. Proteins within the membrane. They give support to the membrane and prevent it from collapsing. Carbohydrates are attached to the integral proteins. These form the GLYCOCALYX. Carbohydrates are attached to the integral proteins. These form the GLYCOCALYX.

The glycocalyx is a sticky coat that allows the cell to bind to other cells. The glycocalyx is a sticky coat that allows the cell to bind to other cells. The glycocalyx also serves as a marker. The glycocalyx also serves as a marker. i.e.: certain antibiotics recognize the i.e.: certain antibiotics recognize the glycocalyx and attach to the cell. glycocalyx and attach to the cell.

Functions of the Plasma Membrane Allows entry into the cell (Endocytosis) Allows entry into the cell (Endocytosis) Phagocytosis – cell eating Phagocytosis – cell eating Pinocytosis – cell drinking Pinocytosis – cell drinking Receptor-Mediated - hormones Receptor-Mediated - hormones Allows movement out of cells (Exocytosis) Allows movement out of cells (Exocytosis)

Cytoplasm Cytosol is a gel like substance which holds all the internal cellular organelles. Contains ions, water, and enzymes.

THE ORGANELLES Perform all the cellular functions. Perform all the cellular functions. “Little Organs” “Little Organs”

MITOCHONDRIA Power plant of the cell Power plant of the cell Produces energy Produces energy

RIBOSOME 2 parts that make proteins. RNA Ribosome

ENDOPLASMIC RETICULUM Subway system of the cell. Subway system of the cell. Network of membrane-walled tubes that twist through the cytoplasm. Network of membrane-walled tubes that twist through the cytoplasm. ROUGH E.R. – have ribosomes attached. ROUGH E.R. – have ribosomes attached. SMOOTH E.R. – do not have ribosomes attached. SMOOTH E.R. – do not have ribosomes attached.

GOLGI APPARATUS Stacks of disk shaped membranes. Stacks of disk shaped membranes.Sort Package proteins Process

LYSOSOMES Sacs containing digestive enzymes that can break down almost all types of biological materials. Sacs containing digestive enzymes that can break down almost all types of biological materials.

PEROXISOMES Contain oxidases (use oxygen to neutralize aggressive compounds known as free radicals). Contain oxidases (use oxygen to neutralize aggressive compounds known as free radicals). Free radicals can damage cellular proteins, membranes, and DNA if left to accumulate. Free radicals can damage cellular proteins, membranes, and DNA if left to accumulate.

CYTOSKELETON System of complex rods that run throughout the cytoplasm. System of complex rods that run throughout the cytoplasm. Microtubules Microtubules Microfilaments Microfilaments

CENTROSOME Contains a matrix and an inner pair of centrioles which are important in cellular division. Contains a matrix and an inner pair of centrioles which are important in cellular division.

NUCLEUS Membrane bound organelle which is the control center for all cellular activity.. Contains DNA – produce instructions for protein synthesis. Contain chromosomes Produce ribsomes in the nucleolus

Related Clinical Terms NECROSIS – cellular death due to disease or injury. NECROSIS – cellular death due to disease or injury. HYPERTROPHY – increase in size. HYPERTROPHY – increase in size. i.e. Muscle cells become hypertrophic in response to exercise. i.e. Muscle cells become hypertrophic in response to exercise.

nucleus Cell membrane Endoplasmic reticulum mitochondria Golgi apparatus

TISSUES Chapter Four

OBJECTIVES for Tissues Be able to list the four basic tissue types and give examples of each. Be able to list the four basic tissue types and give examples of each. Describe the functions of each tissue type. Describe the functions of each tissue type. Describe the cellular components of each tissue type. Describe the cellular components of each tissue type. Describe and identify the morphology of epithelial tissue types. Describe and identify the morphology of epithelial tissue types.

Tissues Cells do not operate independently. Cells do not operate independently. Related cells work and operate together in organized groups. Related cells work and operate together in organized groups. The bottom line: Tissues are clubs of cellular organization.

Four Types of Tissues 1. Epithelial Tissue 2. Connective Tissue 3. Muscle Tissue 4. Nervous Tissue

EPITHELIAL TISSUE Covers the body surface or Lines a body cavity

Epithelial Tissue Occurs at the interface of two different environments. Occurs at the interface of two different environments. i.e. The epidermis is between the inside and the outside of the body. i.e. The epidermis is between the inside and the outside of the body. Protects the body by detecting harmful stimuli. Protects the body by detecting harmful stimuli. i.e. Receptors for pain are found within the skin. i.e. Receptors for pain are found within the skin.

Secretion release of molecules from the cell Absorption bringing small molecules into the cell.

Ion transport – moves ions (charged molecules) across a membrane. Ion transport – moves ions (charged molecules) across a membrane. The epithelium filters fluids that cross the barrier. The epithelium filters fluids that cross the barrier.

Characteristics of Epithelial Tissue 1. Cellularity – composed almost entirely of cells. 2. Specialized Contacts – connects adjacent cells. gap junctions, tight junctions, desmosomes gap junctions, tight junctions, desmosomes 3. Polarity – under surface called the “basement membrane”. 4. Avascular – lacks blood vessels. Receives nutrients through the underlying connective tissue

5. Regeneration – replaces lost/dead cells quickly.

Shapes of Epithelial Tissue Simple Epithelium – one layer Simple Epithelium – one layer Stratified Epithelium – more than one layer Stratified Epithelium – more than one layer Squamous – cells are wider than tall Squamous – cells are wider than tall Cuboidal – cells are just about as tall as wide Cuboidal – cells are just about as tall as wide Columnar – cells are taller than wide. Columnar – cells are taller than wide.

CONNECTIVE TISSUE Types of connective tissue Types of connective tissueFatCartilage Ligaments and Tendons BoneBloodCollagen

Functions of Connective Tissue 1. Support and bind other tissues. (tendons, ligaments) 1. Support and bind other tissues. (tendons, ligaments) 2. Hold body fluids (ground substance). 2. Hold body fluids (ground substance). 3. Defend against infection 3. Defend against infection - mast cells - mast cells - macrophages - macrophages - plasma cells - plasma cells - neutrophils - neutrophils 4. Store nutrients as fat. 4. Store nutrients as fat.

Muscle Tissue Brings about body movement. Brings about body movement. Moves by shortening. Moves by shortening. Three Types: Three Types: 1. skeletal – pulls on long bones. Striated. 1. skeletal – pulls on long bones. Striated. 2. cardiac – only in the heart. 2. cardiac – only in the heart. 3. smooth – no visible striations. Found in walls of hollow visceral organs such as digestive system, urinary organs, blood vessels, and uterus. Mostly involuntary. 3. smooth – no visible striations. Found in walls of hollow visceral organs such as digestive system, urinary organs, blood vessels, and uterus. Mostly involuntary.

Nerve Tissue Uses electrical impulses to transport information. Uses electrical impulses to transport information. Can Regenerate Can Regenerate

Identify the Following: Epidermis Dermis Hair follicle Subcutaneous fat Pore