Cell Anatomy Diagram

Cell

The basic functional unit of life; the smallest subdivision of the body capable of life

Organelles

Membrane-bound structures within the cytoplasm that have specialized functions

Prokaryote

Cells without a nucleus; DNA is not in a seperate organelle

Bacteria and algae

What are two examples of organisms that are prokaryotes?

Eukaryote

Cell with a distinct nucleus surrounded by a protective nuclear envelope; DNA is combined with proteins to form chromosomes; found in all multicellular organisms

Prokaryotes; 1.5 billion years earlier

Which is thought to have developed first: eukaryotes or prokaryotes? How much earlier did they develop?

10-30 µm (micrometers); cells that are too large cannot take in nutrients fast enough to support the cell

What size are most cells restricted to? Why?

Typically long and thin; creates a larger surface area through which nutrients can be absorbed to keep up with increased metabolic needs; skeletal and cardiac muscle cells

What shape are more active cells? Why? What are two examples of more active cells?

Larger and more active cells need multiple nuclei to support increased metabolic needs

Why are some cells multinucleated?

Mitochondrion (Mitochondria)

An organelle that produces 95% of the energy that fuels the cell by processing and breaking down large nutrient molecules (such as glucose); also where cellular respiration takes place (oxygen is consumed, carbon dioxide is excreted)

Elliptical and rounded in shape (ellipsoid)

What shape are mitochondria?

Mitochondria; oxygen; carbon dioxide

Where does cellular respiration take place? What is consumed? What is released?

ATP

What form of energy do mitochondria produce?

They divide through fission (pinching themselves in half)

How do mitochondria create more mitochondria?

Matrix

Enzyme-rich liquid housed in mitochondria

Ribosomes

An organelle that is an important site for protein synthesis; can attach and detach from membranes and move freely within the cell; composed of two globular subunits (protein and rRNA)

Ribosomes

What are the most common organelles in the cell?

Proteins and rRNA

What are ribosomes made of?

Rough Endoplasmic Reticulum (Rough ER)

An organelle where ribosomes produce proteins and cisternae modify proteins; composed of a single lipid bilayer folded into crescent shapes with ribosomes on its surface and is continuous with the nuclear envelope

Smooth Endoplasmic Reticulum (Smooth ER)

An organelle active in the synthesis and storage of lipids (phospholipids and steroids); composed of a single lipid bilayer folded into crescent shapes and is continuous with rough ER

Detoxifies liver cells by breaking down drugs and other harmful chemicals and breaks down glycogen into glucose

What does smooth ER do in the liver?

Golgi Apparatus

Receives proteins produced by ER via transfer sacs, where they are modified (by adding carbohydrates) as they move from fold to fold, packed into vesicles, and sent to other parts of the cell or to the cell membrane; synthesizes polysaccharides; composed of a single lipid bilayer folded into crescent shapes and cisternae

Golgi Apparatus

Which organelle synthesizes polysaccharides?

Cisternae

A flattened membrane vesicle found in the endoplasmic reticulum and Golgi apparatus which increases internal surface area; site of production of ATP in mitochondria and site of the modification processes of proteins in ER

Lysosome

A specialized vesicle formed by the Golgi apparatus; contains hydrolytic or digestive enzymes; fuses with other vesicles and digests them; performs autolysis when cells die

Autolysis

The process when cells die and lysosomes are triggered to release digestive enzymes and digest other portions of the cell

Hydrolytic or digestive enzymes

What types of enzymes are contained in lysosomes?

Golgi Apparatus

Which organelle forms lysosomes?

Peroxisome

Membraneous sacs containing enzymes found throughout cell; detoxifies by removing free radicals; carry two major enzymes (peroxidases and catalases)

Liver and kidney cells

In what cells are peroxisomes most commonly found?

Free Radicals

Normal products of cellular metabolism, but can be harmful to the cell in large quantities because they interfere with the structure of proteins, lipids, and nucleic acids

Peroxidases

Enzyme found in peroxisomes that assists in the conversion of free radicals into hydrogen peroxide

Catalases

Enzyme found in peroxisomes that reduces hydrogen peroxide to water

Inclusions

Packaged units of metabolic products or substances that the cell has engulfed; may be membrane-bound (such as secretory granules, vacuoles, and vesicles) or non-membrane bound (such as lipid droplets and fat globules)

Vacuoles

Which is larger: vesicles or vacuoles?

Centrioles

Small, hollow-like cylinders composed of microtubules that are found in pairs perpendicular to one another; help to organize spindle fibers during cell division

Nucleus

Primary functions are to maintain the hereditary information of the species and to control cellular activities through protein synthesis

Nucleus

What is the largest organelle in the cell?

Nuclear envelope, nucleoplasm, chromatin, and nucleoli

What are the four parts of the nucleus?

Multinucleated Cells

Cells that have multiple nuclei

Anucleated Cells

Cells without a nucleus

Red Blood Cells (RBC); being anucleated results in the cell not being able to divide, make protein or enzymes, or repair themselves resulting in a lifespan of 3-4 months

Which mammalian cells are anucleated (do not contain a nucleus)? How does this affect the cell?

Birds, reptiles, and fish; mammals

Which animal classes have red blood cells that are nucleated? Which animal class has red blood cells that are anucleated?

Approximately 120 days

How long do red blood cells (RBC) survive in dogs?

Approximately 68 days

How long do red blood cells (RBC) survive in cats?

Nucleolus

Contains DNA that governs the synthesis of rRNA; the location where ribosomal subunits are made; not membrane-bound

Nuclear Envelope

Separates nucleus from cytosol; composed of two lipid bilayers and is continuous with Rough ER; contains nuclear pores that allow transport of proteins and RNA

Chromatin

Fibers suspended in nucleoplasm that are made up of DNA and globular proteins called histones; condenses into super-coiled x-shaped structrue called chromosomes during cell division

Nucleosome

A granule consisting of a single strand of DNA wound around eight histone molecules

Chromosomes

Chromatin condensed into supercoiled, x-shaped structures during cell division

Histones

Globular proteins found in the cell nucleus that combined with DNA form chromatin

Nucleoplasm

The gel-like substance that fills the nucleus

Cell Membrane (Plasma Membrane)

Flexible, elastic barrier between inner cytoplasm and extracellular environment; governs the movement of atoms and molecules into and out of the cell; capable of self-repair

The cell will die

What happens if the cell membrane is damaged and intracellular contents are released?

Lipid Bilayer

The structure of the cell membrane is composed of two layers of phospholipid molecules: hydrophilic "heads" on the outside and hydrophobic fatty acid "tails" on the inside

Hydrophilic

Is the "head" of the lipid bilayer hydrophilic or hydrophobic?

Hydrophobic

Is the "tail" of the lipid bilayer hydrophilic or hydrophobic?

Most lipid soluble molecules; O2 (molecular oxygen) and CO2 (molecular carbon dioxide)

Which molecules easily pass through the cell membrane? What are two examples?

Most water-soluble molecules; amino acids, sugars, and proteins

Which molecules do not readily pass through the cell membrane? What are three examples?

They help stabilize the cell membrane

What is the function of cholesterol between the phospholipids in the cell membrane?

Fluid Mosaic

Proteins suspended in the cell membrane lipid bilayer that can move easily throughout the membrane to create a constantly changing pattern

Globular Proteins (Functional Proteins)

Proteins within the cell membrane which are responsible for specialized functions

Integral Proteins

Globular proteins that occur within the lipid bilayer that create channels through which other molecules can pass either passively or require active transport

Selective Channel

Channel made by integral proteins that only permit cetain molecules into or out of the cell

Pores

Channel made by integral proteins that allow passage of water molecules freely and are selective with certain solutes

Peripheral Proteins

Globular proteins which can be bound to the inside or outside surfaces of the cell membrane; sometimes act as enzymes to catalyze specific chemical reactions and may be involved in the mechanics of changing the cell's shape (such as muscle contractions); more restricted in movement due to often being attached to the cytoskeleton or integral proteins

Glycocalyx

Glycoprotein and glycolipid coating covering the surface of some cells that provides improved cell-to-cell adhesion and represents an important biological marker for intercellular recognition for the interactions between the cell and antibodies or viruses

Cell Adhesion Molecules (CAM)

Sticky glycoproteins covering the cell's surface that aids in bonding to extracellular molecules and to other cells, moving past other cells, signaling cirulating cells (such as WBCs to areas of inflammation or infection)

Membrane Receptors

Integral proteins and glycoproteins that act as binding sites on the cell's surface; some play a vital role in contact signaling

Contact Signaling

Cell-to-cell recognition; membrane receptors play a vital role in this process

Chemical Signaling

The process in which membrane receptors send chemical messangers called ligands to bind to specific binding sites on the cell's surfaces and bring about change in cell's activity

Ligands

Chemical messangers that bind to specific binding sites on the cell's surface and bring about change in the cell's activity during chemical signaling

Ligand; a lack of insulin receptors results in a lack of glucose intake, which decreases ATP production, which decreases cellular function causing cells to starve and die

What is insulin an example of? How does a decreased number of insulin receptors affect patients with diabetes mellitus (type 2 diabetes)?

Cilia

Short hair-like extensions of the plasma membrane that occur in large numbers on the exposed surface of some cells; move synchronously to create waves of motion that propel fluid, mucus, and debris across the cellular surface

The upper respiratory tract and the oviduct

What are two locations of cilia in the mammalian body?

Flagella

Long hair-like extensions of the plasma membrane that generally occur singly and are attached to individual cells; aid in propulsion

Sperm

What is the only mammilian cell that has a flagellum?

Basal Bodies

Pairs of centrioles located at the periphery of the cell which form the base of cilia and flagella

Centrioles, pericentriolar material, and asters

What are the three parts of centrosomes?

Centrosome

Region of the cytoskeleton located near the nuclear envelope; responsible for the coordination of building and breaking down microtubules in the cell and is composed of centrioles, pericentriolar material, and asters

Cytoskeleton

Flexible and fibrous three dimensional structure for the cell; changes in accordance to cellular activities and anchors organelles; composed of microtubules, intermediate fibers, and microfilaments

Microtubules

Thickest fibers in the cytoskeleton; grow out from the center of the cell and form cables that organelles attach to; proteins move organelles along fiber throughout the cell; can be easily disassembled and reassembled to form new paths based on the needs of the cell

Intermediate Fibers

Woven, ropelike fibers that possess high tensile strength to resist pulling forces on the cell by acting as internal guide wires; toughest and most permanent part of the cytoskeleton

Microfilaments

Located near cell surface and composed of the contractile protein actin and motor protein myosin; arranged in bundles and meshwork to provide tensional support; play a key role in cell's ability to change shape, break apart during cell division, and form outpouchings and involutions

Cytoplasm

The inner substance of the cell excluding the nucleus; components include cytosol, cytoskeleton, organelles, and inclusions

Cytosol

Viscous fluid of the cell composed of electrolytes, amino acids, and simple sugars; proteins (enzymes) suspended within the fluid that are important in the metabolic activities of the cell