Download Cells and Tissues

Cells Alive
Overview of Cell Parts
Cells
Chapter 3
Prefixes/Suffixes
•
•
•
•
•
Cyt- cell
Endo- in
Hyper- above
Hypo- below
Inter- between
•
•
•
•
•
Iso- equal
Mit- thread
Phag- eat
Pino- drink
-som - body
Now we are ready to review the cell
What is in the cell?
• Most of the cell space is Cytoplasm.
– Cytosol: Gel like fluid where most of
the cells chemical reactions take
place.
• Organelles: Mini cell organs that carry
out specific job functions for the cell.
What is the biggest organelle?
• The nucleus
– The control center for the cell
– Contains DNA
• Contains the message that makes proteins
• Proteins run the cell.
– Contains the organelle= nucleolus
• Nucleolus makes RNA that carries out
DNA’s instructions.
What surrounds the nucleus?
• The Phospholipid membrane
• Two membranes.
• Keeps DNA in
• Only RNA can leave
What are the major organelles?
• Ribosomes: rRNA. Where proteins
are made. Usually on the rough ER.
• Endoplasmic Reticulum:
– rough ER close to the nucleus,
where proteins are made
– Smooth ER makes lipids. No rRNA
present.
• Golgi Apparatus: Ships proteins and
lipids.
More organelles…
• Lysosomes: SOS. Contain digestive enzymes.
Kill invaders and worn out cell parts.
• Mitochondria: Power house of the cell. Makes
ATP (Body runs on ATP energy.)
• Cytoskeleton: Skeleton of the cell. Shape
• Centrioles: Move Chromosomes during cell
division.
• Microtubules: Basis for cilia and flagella
Mitochondria
Ribosome
Endoplasmic
Reticulum
Golgi
Apparatus
Cytoskeleton
Checkpoint
• What is the functional difference
between cilia and flagella?
• What are the structural and
functional differences between
smooth and rough ER?
• Which organelles contribute to
synthesizing protein hormones and
packaging them into secretory
vesicles?
Interactive Cell Parts
Cell Membrane
Fluid-Mosaic
Model
What surrounds the cell?
• The Plasma Membrane. Made out of
Phospholipids.
• May have cilia or microvilli around the
cell.
• Microvilli are in the back of your throat
(filter air) and in your intestine (absorb
food)
Why is the plasma membrane
selectively permeable?
• Works as a barrier. Only allows
certain things in or out of the
cell.
• Means of protection.
• Cells that can not do this are
dead or damaged.
Checkpoint
• List the three main parts of the
cell and explain their functions.
• Why are membranes said to
have selective permeability?
Membrane Transport
Pg. 47-52
What are the two forms of cell
transport?
• Active Transport: uses energy
(ATP) to move molecules against
the concentration gradient or to
move large things.
• Passive Transport: uses NO
energy to move molecules with the
concentration gradient.
What types of Passive transport
does the body use?
• Diffusion: When
molecules move
from high to low
or with the
concentration
gradient.
–Perfume, food
coloring, etc. all
do this.
Simple Diffusion
Diffusion
through a
gated
membrane
channel
What types of Passive transport
does the body use?
• Facilitated Diffusion: Uses
carrier proteins to move substances
without energy with the
concentration gradient.
• Filtration: water and solutes are
forced through a plasma
membrane. Happens in the
Kidneys.
Osmosis
• Osmosis: a specialized form of
diffusion which moves water from
high to low across the plasma
membrane.
Types of Solutions: Pg 50
• Isotonic Solution: Same tonicity
inside and outside the cell. Cell stays
the same size.
• Hypertonic Solution: Higher tonicity
outside the cell. Cell shrinks.
• Hypotonic Solution: Lower tonicity
outside the cell. Cell swells and
“POPS”
Principles
of
osmosis
applied to
red blood
cells
What types of Active Transport do you
use?
• Solute Pumping: Require protein
carriers and energy to move sugars,
Amino Acids, and ions against the
concentration gradient. (Sodium
Potassium pump used in Nerve cells)
Sodium-potassium pump
More Active Transport…
• Bulk Transport: Substances too big to
pass through the plasma membrane.
–Exocytosis: Large things exit the cells
–Endocytosis: Large things enter the cell
• Phagocytosis: Cells that eat- white blood
cell
• Pinocytosis: Cells drink- intestine and
kidneys
Phagocytosis
Checkpoint
• How would having a fever affect body
processes that involve diffusion?
• If 0.9% NaCl is isotonic saline solution for
red blood cells, would a 2% solution of NaCl
cause the red blood cells to expand or shrink?
• What is the key difference between
active and passive transport?
• In what ways are endocytosis and
exocytosis similar and different?
How Proteins are Made
Pgs. 58-62
Overview
What are the names of DNA?
• Chromatin: Unwound DNA
• Chromosomes: Tightly wound
DNA
The Basic Process of Making
Protein
• DNA (In the Nucleus) is
Transcribed into mRNA.
(Transcription)
• RNA brings the message to the
Rough ER where its Translated
into a protein. (Translation)
Overview of
transcription
and
translation
The Details: RNA
(Ribonucleic Acid)
•
•
•
•
•
•
There are three types of RNA
mRNA (messenger RNA)
rRNA (Ribosomal RNA)
tRNA (Transfer RNA)
RNA is Single Stranded, sugar is RIBOSE
The Nitrogen bases for RNA are…
– Adenine bonds to Uracil
– Cytosine bonds to Guanine
The Story
• DNA is stuck in the nucleus.
• RNA is made in the nucleolus.
• mRNA transcribes or re-writes
DNA’s code in RNA and leaves the
nucleus through nuclear pores.
• mRNA brings the message to the
ribosome also known as rRNA.
The fairy tale continues
• Once mRNA is hooked onto the rRNA it
needs the right amino acids to make a
protein.
– Remember 50 or more A.Acids make a
Protein!
• tRNA carries amino acids to the rRNA and
hooks them onto the correct mRNA codon.
– A codon is a three nucleotide sequence
(AUG)
How does the story end?
• When the stop codon is reached the
Amino Acid chain falls off and rolls
into a ball and becomes a protein.
• mRNA goes back to the nucleus to be
reused.
• rRNA stays on the Endoplasmic
Reticulum waiting for the next job.
• tRNA picks up new Amino Acids for
the next job.
Transcription
Protein
elongation
and
termination
of protein
synthesis
during
translation
Checkpoint
• If the DNA template had the
base sequence AGCT, what be
the mRNA base sequence?
• What is the difference between
transcription and translation?
Chromosomes and Mitosis
Pg. 62-65
Two different Cell Divisions
• Meiosis- produces gametes or
sex cells. New cells are
different from the original cell.
• Mitosis- produces new body
cells-like your toes. New cells
are identical to original cell.
DNA in all of its fine forms:
• Chromosomes: Tightly wound
DNA. Resemble an X because two
chromatids are held together.Supercoiled.
• Centromere holds the chromosomes
(Two sister Chromatids) together.
• Chromatid: A single tightly wound
strand of DNA.
And last but not least…
• DNA is your genetic information. In the
shape of a double helix. The nucleotide
pairs are: (Hydrogen bonds)
–Adenine: Thymine
–Cytosine: Guanine
• DNA is broken into segments called
genes which code for proteins.
• Genes give you your physical
characteristics.
Before Eukaryotic Cells
Divide…
• Its chromosomes are replicated.
• Happens through the process of DNA Replication.
DNA Replication:
• DNA needs enzymes (protein) to copy or
replicate itself.
• Double helix unwinds using DNA Helicase.
• DNA Helicase breaks the hydrogen bonds.
• Where the DNA breaks apart is called the
replication fork. DNA polymerase (another
enzyme) adds nucleotides at this point.
How many Chromosomes do
humans have?
• Each somatic cell or body cell has
two copies of 23 chromosomes.
• One copy of the chromosomes (sex
cells or gametes) have 23
chromosomes and are called
haploid or n = 23.
• Two copies of the chromosomes
(somatic cells) have 2n = 46.
There are two types of
Chromosomes.
• Autosomal Chromosomes: or
autosomes are not sex chromosomes.
• Sex Chromosomes: determine the sex of
the individual. The male of the species
determines the sex of the offspring.
Women only have one X chromosome.
Males have an X or a Y.
• XX is a girl
• XY is a boy
Karyotypes: Pictures of your
DNA.
• Why do
we take
pictures?
To find
mistakes
The 5 stages of the Cell Cycle
•
•
•
•
G1: Cell Growth and Metabolism
S: DNA is copied
G2: Cell prepares for division.
Mitosis: Nucleus divides, cell
parts separate.
• Cytokinesis: Cytoplasm divides
Mitosis: The Basic Steps
• Prophase: DNA forms chromosomes.
Nuclear envelope disappears. In Animals
spindle fibers form.
• Metaphase: Chromosomes move to the center
of the cell- pulled by spindle fibers.
• Anaphase: Chromosomes are separated into
chromatids. Spindles shorten pulling
chromatids to opposite ends of the cell.
• Telophase: Nucleus reforms. Chromatids turn
back into Chromatin. Spindles disappear.
Chromosomes
Cell
Division
and
Mitosis
After Mitosis
• Cytokinesis: Cytoplasm
divides in half.
• Animals: The plasma
membrane pinches in half=
Furrow.
• Plants: A cell wall grows
between the two new cells.
Cell Plate.
When control of the Cell cycle is
lost: Cancer is the outcome.
• Cancer: uncontrolled cell division or
death.
• Read pg 66: Normal cells become
cancerous.
Abnormal Cell Functioning - Cancer
• Malignant – uncontrolled cell
division – carried by lymph or
blood to other organs to develop
secondary tumors (metastasis)
–Created by a mutation
• Carcinogens, ultraviolet light
• Benign – remain localized
Mitosis Interaction
Checkpoint
• In which phase of the cell cycle
does DNA replication occur?
• Why must DNA replication
occur before cytokinesis?
• When does cytokinesis begin?
Meiosis: The making of gametes
• One cell eventually creates four
cells
• Each cell is different from the
parent cell
• Haploid
• Meiosis goes through cell
division twice
The Stages of Meiosis
• Prophase 1: Chromosomes are made
and the nucleus membrane disappears.
• Homologous Chromosomes pair and
attach by centromeres.
• Crossing-over occurs. Cross over is
the process of homologous
chromosomes breaking off and
exchanging parts.
– This process is responsible for
making you unique!
Meiosis Animation
Why does Meiosis create
genetic variation?
• Crossing over. Mixes up the traits on each
chromosome.
• Independent assortment. You have 46
chromatids. ½ go to each new cell in Meiosis
1 and again in Meiosis II. No one knows
which chromatids will go to which cell.
• Random Fertilization. Which egg and which
sperm will meet? = a greater genetic
variability.
Making Gametes:
Different for different sexes.
•
•
•
•
• Egg formation: Ovum
Sperm Formation • Oogenesis
Spermatogenesis • One diploid germ cell
One diploid germ
makes one egg and
cell makes four
three polar bodies.
haploid sperm
• Egg must provide the
cells.
food for the zygote
Occurs in the testis (fertilized egg)
throughout the
• Made in ovaries, most
males adult life
before birth
Sexual Reproduction: Two
parents.
• Offspring is genetically
different from parents.
• Great for environmental
change. Easy to evolve.
• Meiosis can better repair
damaged DNA
Checkpoint
• How does crossing-over affect the
genetic content of the haploid
gametes?
• How are haploid and diploid cells
different?
• What are homologous chromosomes?
Sickle-Cell Anemia
• Most common genetic disorder among
people of African descent
• Hemoglobin crystallizes when the
oxygen levels are low and the red
blood cells deform into sickles, which
can clog and rupture capillaries causing
internal bleeding
• Incurable
Chapter Quiz
Cell Case Study
Stem Cells
• Stem
• Cell
• Differentiation