By: Bailey

CHAPTER 3

WHAT IS CELL THEORY?

o Cells are building blocks for plants and animalso Cells are produced by division for preexisting cells

o Cells are the smallest object that perform physiological functions

o Each cell maintains homeostasis at cellular levelo Homeostasis at the tissue, organ, system, and individual

levels reflects the combined and coordinated actions of many cells

o *Homeostasis- the maintenance of a relatively constant internal environment

CELL THEORY

COMPARE FLUID CONTENTS OF CELL WITH THE

EXTRACELLULAR FLUID

High concentration of potassium Relatively high concentrations of

dissolved proteins (enzymes that regulate metabolic operations)

Contains dissolved nutrients, ions, soluble and insoluble

proteins and waste products Contains small quantities of

carbohydrate and large reserves of amino acids and lipids

High concentration of sodium

All body fluid not within the cell

Plasma and interstitial fluid are included in this

Cytosol Extracellular

FLUID CONTENT

CELL MEMBRANE

Composed of

I. Phospholipids

II. Proteins

III. Glycolipids

IV. Cholesterol

* Cytosol is what mostly makes up the cell. Surrounding that is the Phospholipid bilayer, and within that layer are the proteins and channels

I. Separates the inside of the cell from the surrounding

extracellular fluid

II. Controls the entry of ions and nutrients, and eliminates

waste and the release of secretory products

III. Let’s the cell respond and recognize to molecules in its

environmental

IV. Gives tissues a stable structure

Structure Importance

CELL MEMBRANE

CELL AND THEIR ENVIRONMENT

A cell needs to maintain homeostasis

It does this through the cell membrane

Taking in nutrients and obtaining water balance and

giving off waste These all are from the

environment that need to be taken in or let into the

environment from the cell

INTERACTION WITH ENVIRONMENT

STRUCTURE AND FUNCTION

Cell Membrane- isolation,

protection, sensitive,

organization

Cytosol- distributes

materials by diffusion

ORGANELLES

• Cytoskeleton• Microtubules• Microfilaments• Microvilli• Cilia

• Centrioles• Ribosomes

• Nucleus• Endoplasmic reticulum

• Rough ER• Smooth ER

• Golgi Apparatus• Lysosomes• Peroxisomes

NonmembranousOrganelles

MembranousOrganelles

ORGANELLES

• Cytoskeleton- strength, movement of cellular structures

and material• Microtubules- gives

strength to the cell• Microfiliments-

slender protein strand

• Microvilli-absorption of extracellular fluid

• Cilia- movement of materials over

surface• Centrioles- movement

of chromosomes during cell division

• Ribosomes- protein synthesis

NONMEMBRANOUS

• Mitochondria- protein synthesis

• Nucleus- control of metabolism; stores and processes genetic info.

• Nucleolus- site of RNA synthesis

• Endoplasmic Reticulum- synthesis of secretory products; intracellular storage and transport

• Rough ER- secretory protein synthesis

• Smooth ER- lipid and carbohydrate synthesis

• Golgi apparatus-storage, alteration and package of

secretory product and lysosomes

• Lysosomes- intercellular removal of damaged

organelles or of pathogens

• Peroxisomes- neutralization of toxic

compounds

MEMBRANOUS

ENERGY WITHIN CELLS

Mitochondria is the power house of the cell, it makes and stores the “power” so

the cell can function properly

* Metabolic enzymes - Protein-based substances that promote

change in bodily cells…

1. The organelle has a double membrane; the

first surrounds the entire cell, the second surrounds the inner which has many

folds called cristae

2. Cristae increases the surface area exposed to

the fluid contents, matrix

3. Matrix contains metabolic enzymes that perform the reactions that provide energy for cellular

function

Mitochondria How it preforms that…

MITOCHONDRIA

NUCLEUS AS CONTROL CENTER

• The nucleus is surrounded by the nuclear envelope which separates it from the cytosol

• Within the nuclear envelope are perinuclear space

• These allow the nucleus to receive

information about conditions and activities in the cytosol

NUCLEUS

The nucleoplasm contains ions, enzymes, RNA and DNA nucleotides, proteins, small amounts of

RNA and DNA

I. These DNA strands form a chromosome

II. These are then “read” by the nucleus controls by the process of “regulation of protein

synthesis”

III. What is read from the chromosome, the nucleus then tells the cell what needs done and what to

do

NUCLEOPLASM

LIFE CYCLE

Life cycle- Go Phase, G1 Phase, S Phase, G2 Phase,

Gm Phase, Mitosis

LIFE CYCLE

• Go Phase- the cell has normal functions (indefinite time)

• G1 Phase- the cell grows, duplicates its organelles, and preforms protein synthesis (8 or more hours)• S Phase- the cell’s DNA is replicated and

synthesis’s its histones (6-8 hours)• G2 Phase- the cell undergoes protein synthesis’s

(2-5 hours)• Gm Phase- where the cell undergoes mitosis

INTERPHASE

• Prophase (stage 1)- the nuclear envelope disappears

• Metaphase (stage 2)- chromatids move through metaphase plate; microtubules of the spindle

apparatuses attaches to each centromere• Anaphase (stage 3)- the chromatid pairs separate

and the daughter chromosomes move toward the opposite ends to the cell

• Teleophase (stage 4)- the nuclear membranes form, the nuclei enlarge, chromosomes gradually uncoil;

once the chromosomes disappear, nucleoli reappear and the nuclei resemble those of the interphase cell

MITOSIS

IMPORTANCE TRANS -MEMBRANE POTENTIAL

It measures the millivolts across the cell membrane for potential difference that could result from uneven

distribution of the positive and negative ions across a cell membrane

A membrane enzyme called the sodium-potassium pump actively transports ions to compensate for the

sodium and potassium leaks This pump uses the energy of ATP to move sodium and

potassium against their electrochemical gradients The pump compensates for the sodium and potassium

leaks, keeping the resting membrane potential at -70 millivolts

TRANS-MEMBRANE POTENTIAL

HOW CELLS ATTACH

Gap Junction- two cells are held together by an interlocking of membrane proteins, the result is a narrow passage way that

lets small molecules and ions pass from cell to cell Tight Junction- partial fusion of the lipid portions of the two

cell membranes, providing mechanical strength, but blocking the water or solutes between cells

Intermediate Junction- the opposing cell membrane, while maintaining distinct, are held together by a thick layer of

proteoglycans Desmosomes- the opposing cell membranes reinforced by a

network of intermediate filaments that lock the two together , a dense concentration of filament beneath the cell membrane

at a desmosomes anchor it to the cytoskeleton Junction Complex- when all types of junctions including

desmosomes are together in one location

METHODS OF ATTACHMENT

VOCABULARY

Cytology- the study of the structure and function of cells

Transmission electron microscopy- show fine structures of cell membranes and intracellular structures

Scanning electron microscopy- where electrons bounce off exposed surfaces, creates 3D perspective

Extracellular fluid- a watery medium that is on the outside of cells

Cell membrane- outer boundary of the cell

Plasma membrane- another term for cell membrane

Phospholipid bilayer- a cell membrane

Peripheral proteins- attached to the inner membrane surface

Integral proteins- embedded in the membrane

Channels- formed by integral proteins the let water molecules, and other objects pass through it

Cytoplasm- A general term for the material inside of the cell

VOCAB.

Intermediate filaments- provides strength, support, and transports materials within the cytoplasm

Neurofilaments- found in nerve cells and provide structure and support

Thick Filaments- massive strand composed of myosin protein subunits

Microtubules- hollow tubes built from the globular proteins

Tubulin- globular protein

Microvilli- small finger-shaped projections of the cell membrane

Centrioles- is a cylindrical structure composed of short microtubules

Centrosome- cytoplasm surrounding

Cilia- contain nine pairs of microtubules surround a central pair

VOCAB.

Cytoplasm- A general term for the material inside of the cell

Cytosol- or intracellular fluid- dissolved nutrients, ions, soluble, and insoluble proteins and waste products.

Organelles- structures that perform specific functions within the cell

Inclusions- masses of insoluble materials

Non-membranous organelles- in contact with cytosol

Membranous Organelles- surrounded by lipid membranes that isolates them from the cytosol

Cytoskeleton- an internal protein framework the gives the cytoplasm strength and flexibility

Microfilaments- slender proteins strands composed of the protein actin

Actin- a protein found in microfilaments

Myosin- a protein

VOCAB.

Basal Body- an anchored compact for cilia

Flagella- moves cells through the surrounding fluids

Ribosomes- small, dense structure that cannot be seen; they manufacture proteins

Free ribosome- one type of ribosome where its proteins scatter throughout the cytoplasm

Fixed ribosome- attached to the endoplasmic reticulum, its proteins enter here

Mitochondria- small organelle that have a double membrane; makes energy for the cell

Cristae- second inner membrane that contains numerous folds

Matrix- fluid contents of mitochondrion

Respiratory enzyme- produces most of the ATP generated from the mitochondrion

Nucleus- the control center for the cell

Nuclear envelope- surrounds the nucleus and separates it from the cytosol

Perinuclear space- a narrow passage within the nuclear envelope

VOCAB.

Nuclear pores- large pores that permit the movement of ions and small molecules,but too small for DNA

Nucleoplasm- fluid contents of the nucleus

Chromosomes- contain DNA strands

Histones- proteins that bind to DNA strands

Nucleosome- a structure that forms when DNA strands wind around histones

Chromatin- made when chromosomes tangle fine filaments

Endoplasmic reticulum- a network of intracellular membranes

Cisternae- formed by the endoplasmic reticulum; reservoir for water

Rough reticulum- where newly made synthetic proteins undergo chemical modification

Smooth reticulum- synthesis of lipids and carbohydrates

VOCAB.

Golgi apparatus- synthesis and packing, renewal or modification of the cell membrane

Transfer vesicles- how material moves from saccule to saccule

Secretory vesicles- vesicles that contain secretion that will be discharged

Lysosomes- vesicles filled with digestive enzymes; defense against disease

Endocytosis- the process of lysosomes in greater detail

Peroxisomes- smaller then lysosomes; absorb and neutralize toxins

Gated- regulate the passage of materials that travel through channels

Glycocalyx- protects cell membrane; function as receptors; keeps immune system from attacking body

Permeability- objects can pass through it

Impermeability- objects cannot pass through it

Freely permeable- object can pass through without any trouble is said to be

Selectively permeable- permits the passage of some materials

VOCAB.

Diffusion- net movement of material from an area where it’s concentrated from high to low

Concentration gradient- the difference between low and high concentration

Osmosis- the response to the difference in diffusion

Osmotic pressure- force of water movement

Hydrostatic pressure- when pressure is can prevent the entry of molecules

Osmotic concentration/osmolality- total solute concentration in a solution

Tonicity- used when describing osmotic concentration

Isotonic- same solute concentration low and high

Hypotonic- solution has a lower then the cytoplasm

Hemolysis- when a cell burst or explodes

Hypertonic-when concentration is higher than the cytoplasm

VOCAB.