- Developed from Robert Hooke's research - Cells are the building blocks of all plants and animals - All cells come from the division of preexisting cells - Cells are the smallest units that perform all vital physiological functions - Each cell maintains homeostasis at the cellular level

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Cell theory

Developed from Robert Hooke’s research
Cells are the building blocks of all plants and animals
All cells come from the division of preexisting cells
Cells are the smallest units that perform all vital physiological functions
Each cell maintains homeostasis at the cellular level

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Reproductive cells
• Male sperm
• Female oocyte (a cell that develops into an egg)

Sex cells (germ cells)

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-Means body

• All body cells except sex cells

Somatic cells

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-Is the basic structural and functional unit of
life.
-All its activities are dictated by subcellular
structure.

Cell

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Main parts of the cell

Plasma membrane.
Cytoplasm which includes cytosol and organelles
Nucleus.

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Review parts of cell (photo) on powerpoint

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Cytoplasm contains two _______ at
right angles; each _______ is composed
of 9 microtubule triplets in a 9 + 0 array

Centrioles; centriole

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Essential for movement of chromosomes during cell division; organization of mirotubules in cytoskeleton

Centrosome and centrioles

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Proteins organized in fine filaments or slender tubes

Cytoskeleton

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Strength and support; movement of cellular structures and materials

Cytoskeleton

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Lipid bilayer containing phospholipids, steroids, proteins, and carbohydrates

Plasma membrane

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Isolation; protection; sensitivity; support; controls entry and exit of materials

Plasma membrane

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Distributes materials by diffusion

Cytosol

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Are extensions of the plasma

membrane containing microfilaments.

Microvilli

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Increase surface area to
facilitate absorption of
extracellular materials

Microvilli

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Are long extensions of the
plasma membrane containing
microtubules. There are two
types: primary and motile.

Cilia

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Acts as a
sensor. Motile cilia move
materials over cell surfaces

Primary cilium/cilia

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Hollow cylinders of proteolytic
enzymes with regulatory
proteins at their ends

Proteasomes

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Breakdown and recycling of
damaged or abnormal intracellular
proteins

Proteasomes

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RNA + proteins; when fixed, they bound

to rough endoplasmic reticulum; when free, they are scattered in cytoplasm

Ribosomes

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In charge of protein synthesis

Ribosomes

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Stacks of flattened membranes

(cisternae) containing chambers

Golgi Apparatus

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Storage, alteration, and packaging
of secretory products and
lysosomal enzymes

Golgi Apparatus

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Double membrane, with inner
membrane folds (cristae)
enclosing important metabolic
enzymes

Mitochondria

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Produce 95% of the ATP | required by the cell

Mitochondria

Network of membranous channels extending throughout the cytoplasm

Endoplasmic Reticulum (ER)

Synthesis of secretory products; intracellular storage and transport; detoxification of drugs or toxins

Endoplasmic Reticulum (ER)

modifies and packages newly synthesized proteins

Rough ER

synthesizes lipids | and carbohydrates

Smooth ER

Vesicles containing | degradative enzymes

Peroxisomes

``` Catabolism of fats and other organic compounds; neutralization of toxic compounds generated in the process ```

Peroxisomes

Vesicles containing | digestive enzymes

Lysosomes

Intracellular removal of damaged organelles or pathogens

Lysosomes

``` Nucleoplasm containing nucleotides, enzymes, nucleoproteins, and chromatin; surrounded by a double membrane, the nuclear envelope ```

Nucleus

``` Control of metabolism; storage and processing of genetic information; control of protein synthesis ```

Nucleus

``` site of rRNA synthesis and assembly of ribosomal subunits ```

Nucleolus

Review photos of Nucleus and its parts

The cell’s outer boundary; separates intracellular (internal environment) from extracellular fluids (Interstitial Space)

Plasma Membrane

intracellular fluids

internal environment

extracellular fluids

Interstitial Space

Plasma membrane functions

1) Physical Isolation: It’s a selective barrier. 2) Regulation of Exchange with the Environment: • Ions and nutrients enter • Wastes eliminated and cellular products released 3) Structural Support: Anchors cells and tissues 4) Sensitivity to the Environment: Plays a role in cellular communication. (Extracellular fluid composition and chemical signals).

Characteristics of phospholipid bilayer (membrane lipids)

* Hydrophilic heads * Hydrophobic fatty-acid tails * Barrier to ions and water

toward watery environment, | both sides

• Hydrophilic heads

— inside membrane

• Hydrophobic fatty-acid tails

-soluble compounds -Cholesterol “stiffens” the plasma membrane, making it less fluid and less permeable.

• Barrier to ions and water

Membrane Proteins within the membrane

Integral proteins

Bound to inner or outer surface of the membrane

Peripheral proteins

• Attach to inside or outside structures

Anchoring proteins (stabilizers)

Label cells as normal or abnormal

Recognition proteins (identifiers)

Catalyze reactions

Enzymes

Bind and respond to ligands (ions, hormones)

Receptor Proteins

Transport specific solutes through | membrane

Carrier proteins

Regulate water flow and | solutes through membrane.

Channels proteins

Glycocalyx functions

* Lubrication and Protection * Anchoring and Locomotion * Specificity in Binding (receptors) * Recognition (immune response)

Extend outside cell membrane | • Form sticky “sugar coat”

Proteoglycans, glycoproteins, and glycolipids

Is the sticky “sugar coat”

Glycocalyx

The cell is either _________ or __________ to | certain substances

permeable or impermeable

The lipid bilayer is permeable to what?

oxygen, carbon | dioxide, water and steroids

The lipid bilayer is impermeable to what?

glucose and soluble substances.

act as channels and transporters to assist the entrance of certain polar substances, for example, glucose, amino acids, and ions

Transmembrane proteins

Review figure 3-2

All materials inside the cell and outside the nucleus Includes cytosol and organelles

cytoplasm

-Dissolved materials • Nutrients, ions, proteins, and waste products • High potassium/low sodium • High protein • Low carbohydrate/low amino acid and fat

Cytosol (intracellular fluid)

intracellular fluid

cytosol

• Specialized structures with specific functions | -can be membranous or nonmembranous

organelles

• No membrane and direct contact with cytosol • Include the cytoskeleton, microvilli, centrioles, cilia, ribosomes, and proteasomes

nonmembranous organelles

``` • Covered with plasma membrane • Isolated from cytosol • Include the endoplasmic reticulum (ER), the Golgi apparatus, lysosomes, peroxisomes, and mitochondria ```

membranous organelles

Six types of nonmembranous organelles

1. Cytoskeleton 2. Microvilli 3. Centrioles 4. Cilia 5. Ribosomes 6. Proteasomes

Cytoskeleton's three structural proteins for shape and strength

* Microfilaments * Intermediate filaments * Microtubules

thin filaments composed of the | protein actin

Microfilaments

• Provide additional mechanical strength • Interact with proteins for consistency • Pair with thick filaments of myosin for muscle movement

Microfilaments

mid-sized between | microfilaments and thick filaments

Intermediate filaments

* Durable (collagen) * Strengthen cell and maintain shape * Stabilize organelles * Stabilize cell position

Intermediate filaments

large, hollow tubes of tubulin | protein

• Microtubules

* Attach to centrosome * Strengthen cell and anchor organelles * Change cell shape * Move vesicles within cell (kinesin and dynein) * Form spindle apparatus (mitotic Spindle)

Microtubules

Thick filaments

Myosin protein in muscle cells

Review Figure 3-3a The Cytoskeleton

provides strength and structural | support for the cell and its organelles

cytoskeleton

Interactions between cytoskeletal components are also important in ....?

moving organelles and in changing the shape of | the cell.

Review Figure 3-3c

* Increase surface area for absorption | * Attach to cytoskeleton

Microvilli

form spindle apparatus (Mitotic Spindle) | during cell division

Centrioles

cytoplasm surrounding centriole

Centrosome

* Small hairlike extensions | * move fluids across the cell surface

Cilia

``` -consists of nine microtubule triplets (known as a 9 + 0 array). A pair of this oriented at right angles to one another occupies the centrosome. ```

Centriole/s

contains nine pairs of microtubules surrounding a central pair (9 + 2 array). The basal body to which it is anchored has a microtubule array similar to that of a centriole.

Motile cilium

Build polypeptides in protein synthesis

Ribosomes

-in cytoplasm | • Manufacture proteins for cell

Free Ribosomes

-attached to ER | • Manufacture proteins for secretion

Fixed Ribosomes

* Contain enzymes | * Disassemble damaged proteins for recycling

Proteasomes

enzymes in Proteasomes

(proteases)

• Five types of membranous organelles

1. Endoplasmic reticulum (ER) 2. Golgi apparatus 3. Lysosomes 4. Peroxisomes 5. Mitochondria

Endo- =_____ plasm = _____ reticulum =_____

1) within 2) cytoplasm 3) network

are storage chambers within | membranes

Cisternae

Functions of ER

1. Synthesis of proteins, carbohydrates, and lipids 2. Storage of synthesized molecules and materials 3. Transport of materials within the ER 4. Detoxification of drugs or toxins

* No ribosomes attached | * Synthesizes lipids and carbohydrates

Smooth ER

lipids and carbohydrates synthesized by smooth ER

* Phospholipids and cholesterol (membranes) * Steroid hormones (reproductive system) * Glycerides (storage in liver and fat cells) * Glycogen (storage in muscles)

Surface covered with ribosomes

Rough ER

Functions of rough ER

* Active in protein and glycoprotein synthesis * Folds polypeptide protein structures * Encloses products in transport vesicles

Review Figure 3-5a

Vesicles enter forming face and exit maturing face

Golgi apparatus

Functions of Golgi Apparatus

1. Modifies and packages secretions • Hormones or enzymes • Released through exocytosis 2. Renews or modifies the plasma membrane 3. Packages special enzymes within vesicles for use in the cytoplasm

Review Figure 3-6a

Powerful enzyme-containing vesicles

Lysosomes

Lyso means _____ and soma means ______

Dissolve; body

• Formed by Golgi apparatus and inactive enzymes

Primary lysosome

* Lysosome fused with damaged organelle * Digestive enzymes activated * Toxic chemicals isolated

Secondary lysosome

Functions of lysosomes

1. Clean up inside cells | 2. Autolysis

•Lysosomes' Clean Up Inside Cells includes:

* Break down large molecules * Attack bacteria * Recycle damaged organelles * Eject wastes by exocytosis

Auto means _____ and lysis means _____

Self; break

• Self-destruction of damaged cells

Autolysis

* Lysosome membranes break down * Digestive enzymes released * Cell decomposes * Cellular materials recycle

Autolysis

Lysosome activation occurs when:

``` 1) A primary lysosome fuses with the membrane of another organelle, such as a mitochondrion 2) A primary lysosome fuses with an endosome containing fluid or solid materials from outside the cell 3) The lysosomal membrane breaks down during autolysis following injury to, or death of, the cell ```

Review Figure 3-8

• Are enzyme-containing vesicles

• Peroxisomes

• Break down fatty acids, organic compounds, and alcohol. • Abundant in the liver. • Produce hydrogen peroxide (H2O2), Catalase breaks down hydrogen peroxidase to oxygen and water. • Replicate by division

• Peroxisomes

• A continuous exchange of membrane parts by | vesicles

Membrane Flow

* All membranous organelles (except mitochondria) | * Allows adaptation and change

Membrane Flow

-Self-replicate during times of increased cellular demand or before cell division, contain their own DNA and RNA. • Have smooth outer membrane and inner membrane with numerous folds

Mitochondria

smooth outer membrane and inner membrane | with numerous folds

cristae of mitochondria

• Fluid around cristae

Matrix

takes chemical energy from food (glucose) • Produces energy molecule ATP

Mitochondrion

• Glucose to pyruvic acid (in cytosol)

Glycolysis

also known as the Krebs cycle and | the tricarboxylic acid cycle, or TCA cycle

Citric acid cycle

• Pyruvic acid to CO2 (in matrix)

Citric acid cycle

Inner mitochondrial membrane

• Electron transport chain

Steps in Mitochondrial Energy Production

1. Glycolysis 2. Citric Acid Cycle 3. Electron Transport Chain

Mitochondrial Energy Production is called ______ _______ (or ________ ________)

aerobic metabolism (cellular respiration)

Mitochondria use oxygen to break down food and produce ATP • Glucose + oxygen + ADP = carbon dioxide + water + ATP

• Mitochondrial Energy Production--Called aerobic metabolism (cellular respiration)

``` absorb oxygen and short carbon chains, such as pyruvate, and they generate carbon dioxide, ATP, and water. ```

Mitochondria

Review Figure 3-9b

• Largest organelle and the cell’s control center

Nucleus

• Double membrane around the nucleus

Nuclear envelope

• Between the two layers of the nuclear envelope

Perinuclear space

• Communication passages

Nuclear pores

Parts of the nucleus

Nuclear envelope Perinuclear space Nuclear pores ``` DNA Nucleoplasm Nuclear matrix Nucleoli Nucleosomes Chromatin Chromosomes ```

All information to build and run organisms

DNA

Fluid containing ions, enzymes, nucleotides, and | some RNA

Nucleoplasm

Support filaments

Nuclear matrix

* Are related to protein production * Are made of RNA, enzymes, and histones * Synthesize rRNA and ribosomal subunits

Nucleoli

DNA coiled around histones

Nucleosomes

Loosely coiled DNA (cells not dividing)

Chromatin

Tightly coiled DNA (cells dividing)

Chromosomes

Review Figure 3-11

• Instructions for every protein in the body

DNA

* It’s the functional unit of heredity. | * DNA instructions for one protein

Gene

* The chemical language of DNA instructions * Sequence of bases (A, T, C, G) * Triplet code * 3 bases = 1 amino acid

Genetic code

• The Role of Gene Activation in Protein Synthesis

* The nucleus contains chromosomes * Chromosomes contain DNA * DNA stores genetic instructions for proteins * Proteins determine cell structure and function

uncoiling DNA to use it • Promoter “ start” • Terminator “end”

Gene activation

"start" of gene activation

Promoter

"end" of gene activation

Terminator

• Copies instructions from DNA to mRNA (in nucleus)

Transcription

• RNA polymerase produces messenger RNA (mRNA)

Transcription

• Ribosome reads code from mRNA (in cytoplasm)

Translation

• Assembles amino acids into polypeptide chain

Translation

RER and Golgi apparatus produce protein

Processing (The Role of Gene Activation in Protein Synthesis)

True or false: After transcription, the two DNA strands reassociate

True

Review Figure 3-12

Steps in translation

mRNA moves: • From the nucleus through a nuclear pore • To a ribosome in cytoplasm surrounded by amino acids • mRNA binds to ribosomal subunits • tRNA delivers amino acids to mRNA • tRNA anticodon binds to mRNA codon • One mRNA codon translates to one amino acid • Enzymes join amino acids with peptide bonds • Polypeptide chain has specific sequence of amino acids • At stop codon, components separate

Review Figure 3-13

Binding occurs between three nucleotides of the start codon and the three complementary nucleotides in a segment of the tRNA strand known as the _______

anticodon

Steps in translation

``` 1. Binding of Small Ribosomal Subunit 2. Formation of Functional Ribosome 3. Formation of Peptide Bond 4. Extension of Polypeptide 5. Completion of Polypeptide ```

Review Table 3-1 Examples of Genetic Code

• Membrane Transport ---The plasma (cell) membrane is a barrier, but: 1) 2)

* Nutrients must get in | * Products and wastes must get out

determines what moves in and out | of a cell

Permeability

Membrane that lets nothing in or out

impermeable

Membrane that lets anything pass

freely permeable

Membrane that restricts movement

selectively permeable

• Selective permeability restricts materials based | on:

* Size * Electrical charge * Molecular shape * Lipid solubility

• Transport through a plasma membrane can be:

Active or passive

Membrane transport requiring energy and ATP

Active

Membrane transport with no energy required

Passive

Diffusion is what kind of transport?

Passive

Carrier-mediated transport is what kind of transport?

Can be passive or active

Vesicular transport is what kind of transport?

Active

* All molecules are constantly in motion * Molecules in solution move randomly * Random motion causes mixing * Concentration is the amount of solute in a solvent * Concentration gradient

Diffusion

More solute in one part of a solvent than another

Concentration gradient

Review Figure 3-14

• Factors Influencing Diffusion

* Distance the particle has to move * Molecule Size * Smaller is faster * Temperature * More heat, faster motion * Concentration gradient--The difference between high and low concentrations * Electrical forces--Opposites attract, like charges repel

The difference between high and low concentrations

Concentration gradient

Opposites attract, like charges repel

Electrical forces

• Can be simple or channel mediated

Diffusion across Plasma Membranes

Materials that diffuse through plasma membrane by | simple diffusion

• Lipid-soluble compounds (alcohols, fatty acids, and steroids) • Dissolved gases (oxygen and carbon dioxide)

• Factors in channel-mediated diffusion

* Size * Charge * Interaction with the channel — leak channels

Interaction with the channe

Leak channels

• Diffusion across Plasma Membranes with water-soluble compounds and ions

• Channel-mediated diffusion

Review Figure 3-15

--is the diffusion of water across the cell membrane --A Special Case of Diffusion

Osmosis

Characteristics of osmosis

• More solute molecules, lower concentration of water molecules • Membrane must be freely permeable to water, selectively permeable to solutes • Water molecules diffuse across membrane toward solution with more solutes • Volume increases on the side with more solutes

Review Figure 3-16

The osmotic effect of a solute on a cell

Osmolarity and Tonicity

Two fluids may have equal _______, but | different _______

Osmolarity; tonicity

A solution that does not cause osmotic flow of | water in or out of a cell

Isotonic

Iso means ______ and tonos means _______

same; tension

Has less solutes and loses water through osmosis

Hypotonic

Means below

Hypo

Has more solutes and gains water by osmosis

Hypertonic

Means above

hyper

* Gains water | * Ruptures (hemolysis of red blood cells)

A cell in a hypotonic solution:

* Loses water | * Shrinks (crenation of red blood cells)

• A cell in a hypertonic solution:

Rupturing of cells in hypotonic solution is known as

Hemolysis of red blood cells

Shrinking of cells in hypertonic solution is known as

Crenation of red blood cells

is the total concentration of solute | particles in a solution

Osmolarity

is how a solution affects cell volume.

Tonicity

no osmotic flow occurs, and the red | blood cells appear normal.

isotonic saline solution

the water flows into the cell. The swelling may continue until the plasma membrane ruptures, or lyses.

Hypotonic solution

water moves out of the cell. The red blood cells shrivel and become crenated.

Hypertonic solution

Review Figure 3-17

• One transport protein, one set of substrates

Specificity

• Rate depends on transport proteins, not | substrate

Saturation limits

Cofactors such as hormones

• Regulation

``` • Of ions and organic substrates Characteristics: • Specificity • One transport protein, one set of substrates • Saturation limits • Rate depends on transport proteins, not substrate • Regulation • Cofactors such as hormones ```

Carrier-Mediated Transport

Two substances move in the same direction at the | same time

Cotransport

One substance moves in while another moves out

Countertransport

Kinds of Carrier-Mediated Transport

Cotransport and/or countertransport | Active and/or passive transport

• Passive • Carrier proteins transport molecules too large to fit through channel proteins (glucose, amino acids) • Molecule binds to receptor site on carrier protein • Protein changes shape, molecules pass through • Receptor site is specific to certain molecules

Facilitated diffusion

Review Figure 3-18

• Move substrates against concentration gradient

Active transport (primary or secondary) active transport proteins

Requires energy, such as ATP

Active transport

move ions (Na+, K+, Ca2+, Mg2+)

Ion pumps (active transport)

countertransports two ions at the | same time

Exchange pump (active transport)

Kind of transport: • Sodium ions (Na+) out, potassium ions (K+) in • 1 ATP moves 3 Na+ and 2 K

Primary active transport | • Sodium–potassium exchange pump/ Active transport, carrier mediated

Review Figure 3-19

* Na+ concentration gradient drives glucose transport | * ATP energy pumps Na+ back out

Secondary Active Transport

Review Figure 3-20

Materials move into or out of cell in _______

vesicles

• Materials move into or out of cell in vesicles

• Vesicular Transport (Bulk Transport)

``` is active transport using ATP • Receptor mediated • Pinocytosis • Phagocytosis ```

Endocytosis

Endo means

Inside

Kinds of endocytosis

Receptor mediated • Pinocytosis • Phagocytosis

• Receptors (glycoproteins) bind target molecules (ligands) • Coated vesicle (endosome) carries ligands and receptors into the cell

• Receptor-mediated endocytosis

Are receptors

glycoproteins

Are target molecules

ligands

Are coated vesicles

Endosomes

Review Figure 3-21

• Endosomes “drink” extracellular fluid

Pinocytosis

* Pseudopodia | * Engulf large objects in phagosomes

Phagocytosis

Pseudo means _____; podia means ______

False; foot

Granules or droplets are released from the cell

Exocytosis

Exo means

outside

Unequal charge across the plasma membrane is

transmembrane potential

Charges are separated creating a

potential | difference

ranges from –10 mV to | –100 mV, depending on cell type

Resting potential

• Charges are separated creating a potential difference • Unequal charge across the plasma membrane is transmembrane potential • Resting potential ranges from –10 mV to –100 mV, depending on cell type

Transmembrane potential

Most of a cell’s life is spent in a nondividing state. What is this state?

Interphase

Body (somatic) cells divide in three stages. What are these stages?

DNA replication Mitosis Cytokinesis into two daughter cells

duplicates genetic material | exactly

DNA replication

divides genetic material equally

Mitosis

divides cytoplasm and organelles into | two daughter cells

Cytokinesis

unwind the DNA strands

Helicases

1. Promotes bonding between the nitrogenous bases of the DNA strand and complementary DNA nucleotides dissolved in the nucleoplasm 2. Links the nucleotides by covalent bonds

DNA Polymerase

works in one direction

DNA Polymerase

piece together sections of DNA

Ligases

The nondividing period

Interphase

Stages in interphase

• G-zero (G0) phase— specialized cell functions only • G1 phase — cell growth, organelle duplication, protein synthesis • S phase — DNA replication and histone synthesis • G2 phase — finishes protein synthesis and centriole replication

— specialized cell functions | only

G-zero (G0) phase

— cell growth, organelle duplication, | protein synthesis

G1 phase

DNA replication and histone synthesis

S phase

— finishes protein synthesis and | centriole replication

G2 phase

Review Figure 3-24!!! Important

Divides duplicated DNA into two sets of | chromosomes

Mitosis

``` • Divides duplicated DNA into two sets of chromosomes • DNA coils tightly into chromatids • Chromatids connect at a centromere • Protein complex around centromere is kinetochore ```

Mitosis

In mitosis, DNA coils tightly into _______

chromatids

In mitosis, chromatids connect at a _______

centromere

In mitosis, protein complex around centromere is _______

kinetochore

Mitosis divides duplicated DNA into two sets of ________

chromosomes

the DNA strands are loosely coiled and chromosomes cannot be seen.

Interphase

Review Figure 3-24! Important!

``` • Nucleoli disappear • Centriole pairs move to cell poles • Microtubules (spindle fibers) extend between centriole pairs • Nuclear envelope disappears • Spindle fibers attach to kinetochore ```

Prophase

Microtubules are also known as

spindle fibers

• Nucleoli disappear in what phase

Prophase

• Centriole pairs move to cell poles in what phase

prophase

• Microtubules (spindle fibers) extend between | centriole pairs in what phase

prophase

• Nuclear envelope disappears in what phase

prophase

• Spindle fibers attach to kinetochore in what phase

prophase

• Chromosomes align in a central plane (______ | plate)

Metaphase; metaphase plate

Central plane in metaphase

metaphase plate

smaller microtbules that radiate in the cytoplasm in prophase

astral rays

As a result of DNA replication during the S phase, two copies of each chromosome now exist. What phase is this?

Prophase

_______ is connected to its duplicate | copy at a single point, the _______, in prophase

Chromatid; centromere

_______ are the protein-bound areas of the centromere; they attach to spindle fibers forming ______________

Kinetochores; chromosomal microtubules

``` begins as the chromatids move to a narrow central zone called the metaphase plate ```

Metaphase

``` ends when all the chromatids are aligned in the plane of the metaphase plate. ```

Metaphase

* Microtubules pull chromosomes apart | * Daughter chromosomes group near centrioles

Anaphase

• Daughter chromosomes group near centrioles in what phase

Anaphase

• Microtubules pull chromosomes apart in what phase

Anaphase

* Nuclear membranes re-form * Chromosomes uncoil * Nucleoli reappear * Cell has two complete nuclei

Telophase

• Nuclear membranes re-form in what phase

Telophase

• Chromosomes uncoil in what phase

Telophase

• Nucleoli reappear in what phase

telophase

• Cell has two complete nuclei in what phase

telophase

``` begins when the centromere of each chromatid pair splits and the chromatids separate ```

Anaphase

``` each new cell prepares to return to the interphase state. The nuclear membranes re-form, the nuclei enlarge, and the chromosomes gradually uncoil. ```

Telophase

Marks the end of mitosis

Telophase

``` The two daughter chromosomes are Now pulled toward opposite ends of the cell along the chromosomal microtubules. ```

Anaphase

is the division of the cytoplasm into two daughter cells.

Cytokinesis

``` usually begins with the formation of a cleavage furrow and continues throughout telophase. ```

Cytokinesis

The completion of ______ marks the end of cell division.

cytokinesis

the | complex of spindle fibers

Spindle apparatus

Review Figure 3-24

* Division of the cytoplasm * Cleavage furrow around metaphase plate * Membrane closes, producing daughter cells

Cytokinesis

• Membrane closes, producing daughter cells

Cytokinesis

• Cleavage furrow around metaphase plate

Cytokinesis

• Division of the cytoplasm

Cytokinesis

• Slower _______ means longer cell life

mitotic rate

Cell division requires

energy (ATP)

• Muscle cells, neurons ______ divide

rarely

______________ are cells that live only days or hours--replenished by _________

Exposed cells (skin and digestive tract); stem cells

• Normally, cell division _______ cell loss

balances

• Increased cell division is due to:

* Internal factors (M-phase promoting factor, MPF) | * Extracellular chemical factors (growth factors)

Internal factors

M-phase promoting factor, MPF

Extracellular chemical factors

growth factors

• Decreased cell division is due to:

* Repressor genes (faulty repressors cause cancers) | * Worn out telomeres (terminal DNA segments)

Worn out telomeres

terminal DNA segments

Repressor genes lead to decreased cell division. Give an example of an effect of decreased cell division due to repressors

faulty repressors cause cancers

Study Table 3-2 Chemical Factors Affecting Cell Division. IMPORTANT!!!! Towards end of powerpoint

Cancer develops in these steps

* Abnormal cell * Primary tumor * Metastasis * Secondary tumor

* Enlarged mass of cells | * Abnormal cell growth and division

Tumor (neoplasm)

• Contained, not life threatening unless large

Benign tumor

* Spreads into surrounding tissues (invasion) | * Starts new tumors (metastasis)

Malignant tumor

Spreads into surrounding tissues

invasion

Starts new tumors

metastasis

Review Figure 3-25

• All cells carry complete DNA instructions for all | body functions

Differentiation

Cells specialize or ________

differentiate

Cells differentiate or specialize. Why?

* To form tissues (liver cells, fat cells, and neurons) | * By turning off all genes not needed by that cell

• All body cells, except sex cells, contain the same | __ chromosomes

depends on which genes are active | and which are inactive

Differentiation

CH3 Flashcards

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