Cells

Anatomy & Physiology 1

Mitochondria

Mitochondria

Carries out reactions where oxygen is used to break down food, powerhouse of the cell, changes shape continuously, provides ATP for cellular energy

Ribosomes

Made of protein and RNA, sites of protein synthesis, found free in the cytoplasm and as part of the rough ER

Endoplasmic Reticulum (ER)

Fluid filled tubules for carrying substances

Smooth ER

Functions in lipid metabolism and detoxification of drugs and pesticides

Rough ER

Studded with ribosomes, synthesizes proteins

Golgi Apparatus

Modifies and packages proteins, produces different types of packages such as secretory vesicles, cell membrane components, and lysosomes

Lysosomes

Contain enzymes produced by ribosomes, packaged by the golgi apparatus, digest worn-out or non-usable materials within the cell

Peroxisomes

Membranous sacs of oxidase enzymes the detoxify harmful substances like alcohol and formaldehyde and breaks down free radicals (highly reactive chemicals) Replicates by pinching in half

Cytoskeleton

Network of protein structures that extend throughout the cytoplasm, provides the cell with and internal framework, three different types of elements

Centrioles

Road shaped bodies made of microtubules, directs the formation of mitotic spindle during cell division

Cell

The structural and functional unit of any living organism

Plasma Membrane

Outer boundary of the cell

Cytoplasm

Intracellular fluid packed with the functional units called organelles, the material outside the nucleus, site of most cellular activity

Nucleus

Control center of the cell, contains genetic material (DNA), envelopes the nucleolus and chromatin

Extracellular Materials

Substances outside the cell contributing to body mass which provide structure and function

Body Fluids

An extracellular material- interstitial fluid, blood plasma, cerebrospinal fluid

Cellular Secretions

An extracellular material- aids in digestion, acts as lubricants, etc.

Extracellular Matrix

Extracellular material- “cell glue”

Three Regions of the Nucleus

Nuclear Envelope(membrane), nucleolus, chromatin

Nuclear Membrane

Barrier of the nucleus, consists of a double membrane, contains nuclear pores that allow for exchange of material with the rest of the cell

Nucleoli

Center of the nucleus, site of ribosome assembly, ribosomes migrate into the cytoplasm through nuclear pores

Chromatin

Composed of DNA and protein, present when the cell is not dividing, scattered throughout the nucleus, condenses to form chromosomes when the cell divides

Plasma Membrane

Barrier for cell contents, double phospholipid layer, also contains proteins, cholesterol, and glycoproteins

Double Phospholipid Layer of Plasma Membrane

Hydrophilic heads, hydrophobic tails

Plasma Membrane Junctions

Tight junctions, desmosomes, and gap junctions

Tight Junctions

Impermeable junctions, bind cells together into leakproof sheets

Desmosomes

Anchoring junctions that prevent cells from being pulled apart

Gap Junctions

Allow communication between cells

Cytoplasm 3 Major Elements

Cytosol, organelles, inclusions

Cytosol

Fluid that suspends other elements

Organelles

Metabolic machinery of the cell, “little organs” that perform functions for the cell

Inclusions

Chemical substances such as stored nutrients or cell products

3 Different Cytoskeleton Elements

Microfilaments, intermediate filaments, microtubules

Microfilaments

Largest cytoskeletal element

Intermediate Filaments

Medium sized cytoskeletal element

Microtubules

Smallest cytoskeletal element