CH3 Flashcards
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
Reproductive cells
• Male sperm
• Female oocyte (a cell that develops into an egg)
Sex cells (germ cells)
-Means body
• All body cells except sex cells
Somatic cells
-Is the basic structural and functional unit of
life.
-All its activities are dictated by subcellular
structure.
Cell
Main parts of the cell
- Plasma membrane.
- Cytoplasm which includes cytosol and organelles
- Nucleus.
Review parts of cell (photo) on powerpoint
Review parts of cell (photo) on powerpoint
Cytoplasm contains two _______ at
right angles; each _______ is composed
of 9 microtubule triplets in a 9 + 0 array
Centrioles; centriole
Essential for movement of chromosomes during cell division; organization of mirotubules in cytoskeleton
Centrosome and centrioles
Proteins organized in fine filaments or slender tubes
Cytoskeleton
Strength and support; movement of cellular structures and materials
Cytoskeleton
Lipid bilayer containing phospholipids, steroids, proteins, and carbohydrates
Plasma membrane
Isolation; protection; sensitivity; support; controls entry and exit of materials
Plasma membrane
Distributes materials by diffusion
Cytosol
Are extensions of the plasma
membrane containing microfilaments.
Microvilli
Increase surface area to
facilitate absorption of
extracellular materials
Microvilli
Are long extensions of the
plasma membrane containing
microtubules. There are two
types: primary and motile.
Cilia
Acts as a
sensor. Motile cilia move
materials over cell surfaces
Primary cilium/cilia
Hollow cylinders of proteolytic
enzymes with regulatory
proteins at their ends
Proteasomes
Breakdown and recycling of
damaged or abnormal intracellular
proteins
Proteasomes
RNA + proteins; when fixed, they bound
to rough endoplasmic reticulum; when free, they are scattered in cytoplasm
Ribosomes
In charge of protein synthesis
Ribosomes
Stacks of flattened membranes
(cisternae) containing chambers
Golgi Apparatus
Storage, alteration, and packaging
of secretory products and
lysosomal enzymes
Golgi Apparatus
Double membrane, with inner
membrane folds (cristae)
enclosing important metabolic
enzymes
Mitochondria
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
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
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
- Cytoskeleton
- Microvilli
- Centrioles
- Cilia
- Ribosomes
- 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
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
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
- Endoplasmic reticulum (ER)
- Golgi apparatus
- Lysosomes
- Peroxisomes
- Mitochondria
Endo- =_____
plasm = _____
reticulum =_____
1) within
2) cytoplasm
3) network
are storage chambers within
membranes
Cisternae
Functions of ER
- Synthesis of proteins, carbohydrates, and lipids
- Storage of synthesized molecules and materials
- Transport of materials within the ER
- 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
Review Figure 3-5a
Vesicles enter forming face and exit maturing face
Golgi apparatus
Functions of Golgi Apparatus
- Modifies and packages secretions
• Hormones or enzymes
• Released through exocytosis - Renews or modifies the plasma membrane
- Packages special enzymes within vesicles for use
in the cytoplasm
Review Figure 3-6a
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
- 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
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
- Glycolysis
- Citric Acid Cycle
- 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
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
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
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
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
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
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
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
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
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
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
Review Figure 3-19
- Na+ concentration gradient drives glucose transport
* ATP energy pumps Na+ back out
Secondary Active Transport
Review Figure 3-20
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
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
- Promotes bonding between the nitrogenous
bases of the DNA strand and complementary
DNA nucleotides dissolved in the nucleoplasm - 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
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!
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
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
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
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
46
depends on which genes are active
and which are inactive
Differentiation
