Guyton and Hall Chapter 2

The Cell and Its Function

cells

* building blocks of the body
*  providing structure for the body's tissues and organs
* ingesting and converting nutrients to energy
* performing specialized functions
* contains the body's hereditary code

nucleus and cytoplasm

2 major parts of the cell

nucleus

* Control center of the cell
* separated from the cytoplasm by a nuclear membrance

cytoplasm

* A jellylike fluid inside the cell in which the organelles are suspended
* separated from the surrounding fluids by a cell membrane.

protoplasm

different substances that make up the cell

water

electrolytes

proteins

lipids

carbohydrates

5 basic substances of protoplasm

K, Mg, PO4, SO4, bicarbonate and smaller quantities of NA, Chloride and Calcium

important ions in the cell (5)

water

* 70-85 percent of concentration
* principal fluid medium of the cell
* fat cells doesn't have this

proteins

\
* 10-20 percent of the cell mass
* after water, most abundant substances in most cells

structural and functional

2 types of proteins

structural proteins

* present in the cell mainly in the form of long filaments that are polymers of many individual protein molecules
* microtubules that provide the 'cytoskeletons' of such cellular organelles as cilia, nerve axons and mitotic spindles.
* tangled mass of thin filamentous tubules that hold the parts of the cytoplasm and nucleoplasm together in their respective
* Proteins that form an organism’s physical attributes

functional proteins

* entirely different type of protein and are usually composed of combinations of a few molecules in tubular-globular form.
* enzymes
* category of proteins that affect the functional operations of a cell; contrast to structural protein
* category of proteins that affect the functional operations of a cell; contrast to structural protein

Lipids

* grouped together because of being soluble in fat solvents.
* Energy rich organic compounds, such as fats, oils and waxes, hydrogen, and oxygen
* soluble to water

Phospolipids and cholesterol

2 important lipids which together constitute only 2% of the total cell mass.

Carbohydrates

* play a major role in the nutrition of the cell mainly through glucose
* Broken down to simple sugars

Glycogen

If glucose doesn't need to be used right away, it is stores as?

A polymer of glucose

Phospholipids, sphingolipids and cholesterol

The lipid portion of a Eukaryotic Cell includes \____________, \______________, and \_____________

Ions, glucose and urea

Middle membrane is impermeable to the usual water-soluble substances.

oxygen, CO2 and alcohol

Fat soluble that can penetrate the portion of the membrane with ease.

Phospholipids

the most abundant lipid in the plasma membrane

Hydrophilic

One end of each phospholipid molecule is soluble in water and that is?

Hydrophobic

One end of each phospholipid molecule is soluble in fat and that is?

Phosphate

What end is hydrophilic?

Fatty acid

What portion is hydrophobic?

Sphingolipids

derived from sphingosine

Nerve cells

Sphingolipids also have hydrophobic and hydrophilic groups and are present in small amounts in the cell membranes, esp \_____

Complex sphingolipids in cell membranes

Are thought to serve several functions, including protection fro harmful environmental factors, signal transmission and as adhesions sites for extracellular proteins.

Fat

The cholesterol molecules in the membrane are also lipids because their steroid nuclei are highly \_____ soluble.

False

T/F

Cholesterol does not control much of the fluidity of the membrane.

integral and peripheral

two types of membrane proteins

Integral proteins

\-protrude all the way through the membrane

\-penetrate the hydrophobic interior of the lipid bilayer

Peripheral proteins

Attached only to one surface of the membrane and do not penetrate all the way through.

Diffuse

Integral proteins provide structural channels or pores through which water molecules and water soluble substances especially ions can \_____ between the ECF and ICF.

Carrier proteins

Other integral proteins act as \_____ for transporting substances that otherwise could not penetrate the lipid bilayer.

Active transport

Enzymes

Sometimes these carrier proteins even transport substances in the direction opposite to their electrochemical gradients for diffusion which is called \_____. Still others act as \_____.

Receptor

Integral membrane proteins can also serve as \_____ for water-soluble chemicals such as \_____ hormones that do not penetrate the cell membrane.

Ligands

Interaction of cell membrane receptors with specific \_____ that bind to the receptor causes conformational changes in the receptor protein.

Conveying information

Integral proteins spanning the cell membrane provide a means of \_____ about the environment to the cell interior.

Peripheral protein molecules

Pores

\_____ are often attached to the integral proteins. These function almost entirely as enzymes or as controllers of transport of substances through the cell membrane \_____.

Glycocalyx

superficial membrane carbohydrates and proteins (glycoproteins, glycolipids) involved in cell recognition, binding extracellular structures, lubrication of cell surface

Glycoproteins

Glycolipids

Membrane carbohydrates occur almost invariably in combination with proteins or lipids in the form of? (2)

Proteoglycans

Mainly carbohydrate substances bound to small protein cores - are loosely attached to the outer surface of the cell as well.

Glycocalyx

Entire outside of the surface of the cell often has a loose carbohydrate coat.

1. Many of them have a negative electrical charge, which gives most cells an overall negative surface charge that repels other negatively charged objects.
2. Glycocalyx of some cells attaches to the glycocalyx of the other cells, thus attaching to one another.
3. Many of the CHO act as a receptor substances for binding hormones such as insulin; when bound, this combination activates attached internal proteins that, in turn, activate a cascade of intracellular enzymes.
4. Some CHO moieties enter into immune reactions.

4 important functions of the CHO moieties attached to the outer surface of the cell

Cytoplasm

Filled with both minute and large dispersed particles and organelles.

Cytosol

Jelly-like fluid portion of the cytoplasm in which particles are dispersed and contains mainly dissolved CHONs, electrolytes and glucose.

Mitochondria

Endoplasmic Reticulum

Golgi Apparatus

Mitochondria

Lysosomes

Peroxisome

5 especially important organelles

Endoplasmic Reticulum

Shows a network of tubular and flat vesicular structures in the cytoplasm

\
An organelle that helps process molecule made by the cell and transports them to their specific destinations inside or outside the cell

Rough ER

ER that functions to produce proteins.

Smooth ER

ER that functions to produce lipids.

Ribosomes

Attached to the outer surfaces of many parts of the ER are large numbers of minute granular particles.

Granular ER

When large numbers of granular are present, it is called?

RNA

Proteins

The ribosomes are composed of a mixture of \_____ and \_____ and they function to synthesize new protein molecules in the cell.

Agranular ER

Part of the ER has no attached ribosomes

Lipid

Intrareticular enzymes

The agranular reticulum functions for the synthesis of \_____ substances and for other processes of the cells promoted by \_____.

Golgi Apparatus

Closely related to ER

\
Has membrane similar to those of agranular ER \n \n Usually composed of 4 or more stacked layers of thin, flat, enclosed vesicles lying near one side of nucleus.

Secretory

The Golgi Apparatus is prominent in \_____ cells.

Lysosomes

Secretory vesicles

Other cytoplasmic components

Substances entrapped in the ER vesicles are transported from the ER to golgi apparatus and then processed to form? (3)

Lysosomes

Are vesicular organelles that form by breaking off from the Golgi apparatus and then dispersing throughout the cytoplasm.

1. Damaged cellular structures
2. Food particles that have been ingested by the cell
3. Unwanted matter such as bacteria.

The lysosomes provide intracellular digestive system that allows the cell to digest? (3)

Hydrolase

Lysosomes mainly contains \_____ which is essentially a digestive enzyme and they break down protein into amino acids, glycogen into glucose and lipids into fatty acids and glycerol.

Peroxisome

Are similar to lysosome but are different in 2 ways:


1. Formed by self-replications (budding off from the smooth ER)
2. Contain oxidases rather than hydrolases.

Oxidases

Combines oxygen with hydrogen and form hydrogen peroxide.

hydrogen peroxide (H2O2)

Highly oxidizing substance and is used in association with catalase, another oxidase enzyme present in large quantities in peroxisome, to oxidize many substances that might otherwise be poisonous to the cell.

Catabolize

Major function of peroxisome is to \_____ long chain fatty acids.

Secretory vesicles or secretory granules

Almost all such secretory substances are formed by the ER - Golgi apparatus system and are then released from the Golgi apparatus into the cytoplasm i the form of storage vesicles called?

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

\
Self replicative

\
Contains DNA

Cardiomyocytes

cardiac muscle cells that use large amounts of energy and have far more mitochondria than do adipocytes (fat cells) which are more less active and use less energy.

Cristae

many infoldings of the inner membrane form shelves or tubules onto which oxidative enzymes are attached.

Matrix

Inner cavity of the mitochondrion is filled with a \_____ that are necessary for extracting energy from nutrients.

ATP (adenosine triphosphate)

The liberated energy is used to synthesize a high energy substance called?

DNA

Basic chemical of the nucleus that controls replication iof the cell

Cell cytoskeleton

Network of fibrillar proteins organized into filaments or tubules.

\
Primary function of microtubules is to act as a _____ providing rigid physical structures for certain parts of cells. \n \n Not only determines cell shape but also participates in cell division, allows cells to move, and provides a track-like system that directs the movement of organelles within the cells

Ectoplasm

Outer zone of the cytoplasm

Actin and myosin filaments

Are organized into a special contractile machine that is the basis for muscle contraction (2)

Tubulin

Microtubules

a special type of stiff filament composed of polymerized \_____ molecules is used in all cells to construct strong tubular structures, the \_____.

Nucleus

Control center of the cell

Genes

Nucleus contains large quantities of DNA that comprises?

\
Also control and promote reproduction of the cell

Mitosis

Genes first reproduce to create 2 identical sets of gens; then the cells splits by a special process called \_____ to form 2 daughter cells, each of which receives 1 or 2 sets of DNA genes.

Interphase

Mitosis - nucleus revealing darkly staining chromatin material throughout the nucleoplasm.

Nuclear Membrane

Also called nuclear envelope, is actually 2 separate bilayer membranes, one inside the other.

Nuclear Pores

Nuclear membrane is penetrated by several thousand \_____.

Nucleoli

The nuclei of most cells contain one or more highly staining structures called?

Nucleic acid

Essential life-giving constituent of the small virus embedded in a coat of protein.

\
Composed of the same basic nucleic acid constituents (DNA or RNA) found in mammalian cells.

Organelles

In still later stages of life, particularly the rickettsial and bacterial stages, \_____ developed inside the organism, representing physical structures of chemical aggregates that perform functions in a more efficient manner than can be achieved by dispersed chemicals throughout the fluid matrixt.

Nucleus

Distinguishes this type of cell from all lower forms of life

\
Provides a control center for all cellular activities \n \n Provides for reproduction of new cells generation after generation, with each new cell having almost exactly the same structure as its progenitor.

Diffusion

Active transport

Most substances pass through the cell membrane by? (2)

Diffusion

Involves simple movement through the membrane caused by the random motion of the molecules of the substance

\
Substances move either through cell membrane, pores or, in the case of lipid-soluble substances, through the lipid matrix of the membrane.

Active transport

Involves the actual carrying of a substance through the membrane by a physical protein structure that penetrates all the way through the membrane.

Endocytosis

Very large particles enter the cell by a specialized function of the cell membrane called?

Pinocytosis and Phagocytosis

The principal form of endocytosis are? (2)

Pinocytosis

Cell drinking

\
means ingestion of minute particles that form vesicles of ECF and particulate constituents inside the cell cytoplasm.

Phagocytosis

Cell eating

\
Ingestion of large particles such as bacteria, whole cells, or portions of degenerating tissue.

Adherence

Engulfment

Phagosome formation

Fusion with lysosomal granules

Destruction of the target

Phagocytosis steps

Pinocytosis

Only means by which most large macromolecules such as most protein molecules can enter cells.

Coated pits

Receptors generally are concentrated in small pits on the outer surface of the cell membrane.

\
Receptor-mediated endocytosis involves _____, which are indentations on the surface of a plasma membrane that contain receptor proteins.

Clathrin

On the inside of the cell membrane beneath these pits is a latticework of fibrillar protein.

Pinocytotic vessel

Invaginated portion of the membrane breaks away rom the surface of the cell forming a \_____ inside the cytoplams of the cell.

Macrophages

Some white blood cells

Only certain cells have the capability of phagocytosis, most notably the? (2)