Cell Energy. Main Topics Photosynthesis Cellular Respiration.
Cells Cell Structure and Function Photosynthesis Cellular Respiration Cell Growth and Division.
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Transcript of Cells Cell Structure and Function Photosynthesis Cellular Respiration Cell Growth and Division.
Cells
Cell Structure and FunctionPhotosynthesis
Cellular RespirationCell Growth and Division
Cell Structure and Function
(Chapter 7)
Life is Cellular How did the Cell Theory develop?
Cell Theory Guided Reading activity Know the contributions of the following
scientists: Robert Hooke (1665) Anton van Leeuwenhoek (1674) Matthias Schleiden (1838) Theodor Schwann (1839) Rudolph Virchow (1855) Janet Plowe (1931) Lynn Margulis (1970)
Prokaryotes vs. Eukaryotes Prokaryotes = Eukaryotes=
Use my website to determine the major differences between eukaryotes and prokaryotes.
Cell Structures Use the webquest on animal and plant cell
organelles and their functions as notes for this section.
Go to my website, click on links, then click on “cells alive!”
Or go to http://www.cellsalive.com for more information!
The Compound Microscope Review the
microscope lab activity as notes for this section! Know the parts of the
microscope and be able to accurately label a microscope diagram!
Know how to make a wet mount slide!
Cellular Diversity
Protists: Webquest on
“What are Protists?”
Protista lab activity
Animal and Plant Cells: Observing Animal
and Plant Cells lab activity
Protist Lab Video Clips Paramecium:
http://www.youtube.com/watch?v=l9ymaSzcsdY&NR=1&feature=fvwp
Euglena: http://www.youtube.com/watch?v=7DALQ-XLJ4
Q&feature=related Amoeba:
http://www.youtube.com/watch?v=I3Jo7moaLdI&feature=related
Levels of Organization in Multicellular Organisms
Use the Levels of Organization webquest as notes for this section.
Structure and Function
Choose a cell type and research how it’s structure helps it
function.
20 minute research activity:
Cells performing the same function often are similar in shape
Question: “How does the cell shape affect it’s function/allow it to function?”
Choose from one of these cell types: Neuron Red Blood Cell Cheek Epithelial Cell
Product Ideas: PowerPoint, Poster, graphic organizer, song,
interpretive dance, model, acrostic poem, concept map
Neuron
Cheek Epithelial Cell
Red Blood Cell
Neuron Notes…
Cheek Epithelial Cell Notes…
Red Blood Cell Notes…
Homeostasis in the Human Body Use the Homeostasis in the Human Body
Webquest as notes for this section.
The Cell Membrane
Structure and Function“Fluid Mosaic Model”
The Cell Membrane Regulates what enters and leaves Provides protection and support Made up of:
Phospholipids (“lipid bilayer”) Integral and Peripheral Proteins Carbohydrate chains (glycoproteins) Cholesterol
Cell membrane structure
Where are they found? Found in:
Nucleus Cell membrane Golgi apparatus endoplasmic reticulum lysosomes mitochondria (basically any
membrane bound organelle!)
Structure Lipid bilayer is made
of the following: 2 types of proteins:
Integral proteins Peripheral proteins
3 types of lipids: Membrane
Phospholipids Membrane glycolipids Cholesterol
Integral proteins Transmembrane
proteins (or integral proteins) Amphipathic =
hydrophobic and hydrophilic regions
Peripheral proteins Peripheral proteins
linked at the cytoplasmic surface (by attachment to a fatty acid chain)
linked at the external cell surface (attached by an oligosaccharide)
may be bound to other membrane proteins
Membrane Phospholipids These have a polar
head group and two hydrocarbon tails
It is connected by glycerol to two fatty acid tails
One of the tails is a straight chain fatty acid (saturated). The other has a kink in the tail (unsaturated).
Membrane glycolipids Glycolipids are also a
constituent of membranes.
These components of the membrane may be protective, insulators, and sites of receptor binding.
Cholesterol The amount of
cholesterol may vary with the type of membrane.
Plasma membranes have nearly one cholesterol per phospholipid molecule.
Other membranes (like those around bacteria) have no cholesterol
Cholesterol (continued) Function:
This makes the lipid bilayer less deformable Without cholesterol (such as in a bacterium) a
cell would need a cell wall. Also keeps the cell membrane from becoming
too stiff.
Fluid Mosaic Model Based on what you know about the
structure and function of the cell membrane what does the fluid mosaic model mean?
Diffusion, Osmosis, and Active Transport Molecular Workbench Activity Complete this online and use your analysis
packets as additional notes. We will be completing this in class!
Movement Through the Membrane
NO ENERGY (ATP) REQUIRED
ENERGY (ATP) REQUIRED
[high] [low]
[low] [high]
Materials can move through the membrane by: Diffusion
Osmosis Facilitated Diffusion Active Transport
Protein Pumps Endocytosis Exocytosis
Diffusion Requires no energy (ATP) Moves from an area of High concentration
low concentration until dynamic equilibrium is reached.
Dynamic equilibrium activity http://www.stolaf.edu/people/giannini/flash
animat/transport/diffusion.swf
Osmosis A type of diffusion (no energy needed) Allows water molecules to pass easily
through the selectively permeable membrane.
Solution = solute + solvent Solute = sugar (or another dissolved
substance)…CANNOT go through the membrane
Solvent = water…CAN go through the membrane
Osmosis ONLY water moves The solute stays put on one side or the
other Water moves back and forth according to
the concentration of water on each side of the membrane
http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.swf
Osmotic Pressure Isotonic solutions
The 2 solutions have equal concentrations of solute and solvent.
Hypotonic solutions One solution has less solute and more water
compared to the other solution. Hypertonic solutions
One solution has more solute and less water compared to the other solution.
What would happen? What would happen if…
You placed a selectively permeable membrane “bag” with a hypotonic solution into a beaker with a hypertonic solution?
Which way would the water flow? What would happen to the bag? What would happen to the beaker? How do you know? How could you test this?
Facilitated Diffusion Diffusion with the help of transport
proteins No energy required http://www.stolaf.edu/people/giannini/flash
animat/transport/channel.swf
Active Transport Cell uses energy Actively moves molecules to where they
are needed Movement from an area of low
concentration to an area of high concentration
3 MAIN TYPES: 1. Protein pumps2. Endocytosis (BULK TRANSPORT)3. Exocytosis (BULK TRANSPORT)
Types of Active Transport1. Protein Pumps -transport proteins that
require energy to do work Example: Sodium / Potassium Pumps are
important in nerve responses. http://www.stolaf.edu/people/giannini/flashani
mat/transport/secondary%20active%20transport.swf
Protein changes shape to move molecules: this requires energy!
Types of Active Transport2. Endocytosis: taking bulky material into a
cell Uses energy Cell membrane in-folds around food particle “cell eating” Forms food vacuole & digests food This is how white blood cells eat bacteria!
Types of Active Transport3. Exocytosis: Forces material out of cell in
bulk membrane surrounding the material fuses
with cell membrane Cell changes shape – requires energy EX: Hormones or wastes released from cell http://www.stolaf.edu/people/giannini/flashani
mat/cellstructures/phagocitosis.swf
Photosynthesis
Energy and Life Energy = ability to do work Source of energy on Earth = sun Autotrophs use light energy from the
sun (or other sources) to make food. Heterotrophs obtain energy from foods
consumed. Energy comes in many forms
Light, heat, and electricity
ATP “like a fully charged battery” One of the principle chemical compounds
that is used to store energy Adenosine triphosphate (ATP)
ADP “like a ½ charged battery” When energy is released from ATP
converts to ADP and a phosphate group
Using Biochemical Energy Cells use this energy for:
Mechanical work, chemical work, transport work
Basically, all cellular processes ATP in cells = good for only a few seconds
of activity (not efficient storage) 1 molecule of glucose stores more than 90x’s
the chemical energy of ATP Cells can generate ATP as needed from the
glucose in carbohydrates consumed during feeding
Investigating Photosynthesis Jan van Helmont
Concludes plants gain most of their mass from water
Joseph Priestly Concludes that plants release a substance that
keeps a candle burning (oxygen) Jan Ingenhousz
Concludes that plants produce oxygen bubbles in the light but not in the dark (they need sunlight).
Photosynthesis Equation
Light and PigmentsPhotosynthesis requires: Light
From sunlight (A mixture of different wavelengths of light)
Chlorophyll (a pigment found in chloroplasts that absorbs light energy) 2 main types:
Chlorophyll a (absorbs violet and red light) Chlorophyll b (absorbs blue and red light)
Structure of a Chloroplast
NADPH When sunlight hits chlorophyll a double
bond is broken releasing a high energy electron.
This high energy electron requires a special carrier called NADP+.
Once the electron is combined with NADP+ it becomes NADPH.
NADPH carries this energy to other reactions around the cell.
Light-Dependent Reactions Use energy from sunlight to produce
Oxygen, ATP and NADPH. Photosystem II is the first to absorb light
(discovered after photosystem I) Light smashes high energy electrons out of the
chlorophyll molecules which are carried to electron transport chains in the thylakoid membrane.
The lost electrons from the chlorophyll molecule are replaced by breaking water molecules apart which releases oxygen.
Light-Dependent Reactions (Continued) High energy electrons move from
Photosystem II to photosystem I. Energy from this transport pumps H+ ions from
the stroma into the inner thylakoid. Pigments in photosystem I use sunlight to
release additional high energy electrons and a H+ ion becomes NADPH
Inside of thylakoid membrane becomes positively charged (from the H+ ions)/outside negatively charged Charge difference allows ATP to be made.
Light-Dependent Reactions (Continued) ATP formation=
H+ ions move through a protein called ATP synthase.
As it rotates the protein binds ADP with an additional phosphate to create ATP!
The Calvin Cycle:OR the light-independent reactions ATP and NADPH from the light reactions are
required to produce high-energy sugars. Step 1: CO2 enters the cycle and is combined with
6 5-Carbon molecules forms 12 3-Carbon molecules
Step 2: Energy from ATP and NADPH are used to convert the 12 3-Carbon molecules into higher-energy forms
The Calvin Cycle:OR the light-independent reactions Step 3: 2 3-Carbon molecules are used to
make a 6-Carbon sugar (glucose!) Step 4: The 10 remaining 3-Carbon
molecules are converted back into 6 5-carbon molecules These are reused in the next cycle!!!
Factors affecting photosynthesis Availability of Water
Shortage of water can slow or stop photosynthesis Temperature
Plants function best between 0°C and 35°C (temperatures above or below may damage enzymes and slow or stop photosynthesis)
Intensity of light Increasing intensity increases rate of photosynthesis
until maximum rate of photosynthesis is reached.
Photosynthesis Molecular Workbench We will be completing this online
together…Use your analysis packets as additional notes. We will be completing this in class!
Cellular Respiration
Chemical Pathways Energy in food:
Calorie = amount of energy needed to raise the temp. of 1 g of water 1°C
Gradually release energy from glucose and other food compounds
2 Pathway for energy release Aerobic (O2 present) Anaerobic (in the absence of O2)
Cellular Respiration Overview
Oxygen + glucose carbon dioxide +water +energy
6O2 + C6H12O6 6CO2+ 6H2O + ATP
3 main stages: Glycolysis The Krebs cycle (or “citric acid cycle”) Electron Transport Chain (or “oxidative
phosphorylation”)
Glycolysis (glyco- = sweet; lysis = breaking) Occurs in the cytoplasm near the mitochondion No oxygen is required for glycolysis 1 molecule of glucose (6C) is broken into 2
molecules of pyruvic acid (3C) (pyruvate) Needs to use 2 ATP to get started Generates 4 ATP at the end Net ATP total = 2 ATP
Produces 4 molecules of NADH (high energy electron carrier) transports to other reaction sites
What happens if there is no oxygen? Fermentation!
Cells convert NADH back into NAD+ by passing electrons back to pyruvate
Allows glycolysis to continue to produce ATP (not efficient)
2 main types: Alcoholic Fermentation (bacteria and yeast) Lactic Acid Fermentation (humans)
Alcoholic Fermentation Yeasts and bacteria Beer, wine, and bread production Pyruvic acid + NADH alcohol +
CO2 +NAD+
In bread: CO2 makes the bread rise Alcohol is baked off
Lactic Acid Fermentation Pyruvic acid is converted to lactic acid
This regenerates NAD+ so glycolysis can continue to generate ATP
Pyruvic acid + NADH lactic acid + NAD+
Produced in the muscles when there is not enough O2 causing burning/pain Example: Wall sit of death
What if there is oxygen present after glycolysis? Krebs cycle and electron transport chain!!! Most powerful electron acceptor =
oxygen!!! Uses the remaining 90% of energy still
trapped in the glucose molecule after glycolysis!
The Krebs Cycle Step # 1:
Pyruvic acid enters the mitochodrion A carbon is removed forming CO2 and electrons
are removed forming NADH CO2 is combined with coenzyme A and is
transformed into acetyl-CoA Acetyl-CoA adds a 2-C acetyl group to a 4C
compound forming citric acid.
The Krebs Cycle (continued) Step # 2:
Citric acid is broken down into a 5C compound then a 4C compound
2 molecules of CO2 are released, electrons form NADH and FADH2, and 1 ATP is generated
From one molecule of pyruvic acid= 4 NADH, 1 FADH2, 1 ATP But remember 2 molecules of pyruvic acid are made
from each molecule of glucose!!! (so this process happens twice)
Electron Transport The high energy electrons in FADH2 and
NADH from the Kreb’s cycle Are transported to the inner membrane of the
mitochondrion In prokaryotes ETC is in the cell membrane
The ETC uses the high energy electrons to make ATP
Electron Transport (continued) High energy electrons are passed to a series of
carrier proteins in the membrane As electrons move to each carrier, H+ ions are moved to
the inner membrane space These will be used later to generate ATP via ATP
synthase At the end an enzyme that combines the
electrons with hydrogen ions and oxygen to form water
Energy Totals Aerobic Respiration = 36 ATP
Uses 38% of the total energy of a molecule of glucose
The rest is released as heat (body heat!) More efficient than a gasoline car engine We are an efficient combustion engine!!!
Anaerobic Respiration = 2 ATP
Energy and Exercise Quick energy (a sprint)
ATP is short-lived and is used right away Stored ATP used in a few seconds of intense
activity Then, ATP is generated via lactic acid
fermentation
Energy and Exercise Long-term energy (marathon)
For exercise longer than 90 seconds cellular respiration is the only way to generate enough ATP to sustain activity.
Stored energy = glycogen (breaks down into glucose and is stored in muscles)
Lasts only about 15-20 minutes Once glycogen is depleted body uses fat
stores (good for weight loss!)
Linking to Homeostasis Rate of Cellular Respiration Inquiry (RITES
lab using BIOPACS) Heart Rate Monitor Design an experiment to test the rate of
cellular respiration How does cellular respiration work to
maintain homeostasis in the human body? Include body systems in your response.
Comparing Cellular Respiration to Photosynthesis Generate a chart comparing the following:
Photosynthesis Cell Respiration
Function
Location
Reactants
Products
Equation
Cellular Respiration Molecular Workbench Complete this online and use your analysis
packets as additional notes. We will be completing this in class!
TedX talk –Discovering ancient climates in oceans and ice: Rob Dunbar on TED.com
Cell Growth and Division
Limits to Cell Size Activity Draw an example of a town with the
borders being the edges of the paper There is one main road into and out of the
town. Think of a cell and the parts needed to run the
cell. Recreate these parts as parts of a town Don’t forget: nutrients (food trucks) and
waste (dump trucks)
Limits to Cell Size Activity Increase the Population by THREE TIMES What does this do to the demands put on
the town?: What does this do to the Traffic? What does this do to the Waste and Nutrients? What does this do to the Resources needed to
thrive? What does this do to the people who run the
town?
Limits to Cell Size Activity Based on the activity…
What are the 2 limits to cell size?What happens when a cell becomes
too big?
Cell Growth 2 limits to cell size =1. The larger the cell becomes the more demands
the cell places on its DNA2. The cell has difficulty moving nutrients and
waste across the membrane Thus the size of a cell is limited
As the length of a cell increases… Volume increases faster than its surface area
What happens when a cell gets too big? IT DIVIDES!!! Cell division
1 cell 2 daughter cells (exact copies of the original)
Prokaryotes easy Circular DNA copies then divides
Eukaryotes more involved Complex DNA (23 pairs of chromosomes =
46 total)
The Cell Cycle Average
time = 16 – 20
hours
G1 Phase Cell Growth
Intense growth and activity Increases in size Synthesizes new proteins and organelles
The Cell Cycle
S Phase DNA Synthesis
Creates a duplicate set of chromosomes G0 (or R on diagram) = Point of no return
Chromosome Structure
“supercoils”
Human Chromosomes (Karyotype)
The Cell Cycle
G2 Phase Preparation for Mitosis
Shortest of the 3 phases of interphase (G1, S, and Gs)
Organelles and proteins needed for cell division are produced.
The Cell Cycle
Mitosis Prophase Metaphase Anaphase Telophase Cytokinesis
Prophase Chromosomes condense (“appear”) Nuclear envelope dissolves Centrioles move to opposite sides (poles) of
the cell
Metaphase Centrioles send out spindle fibers that attach to
the chromosomes Chromosomes are lined up in the middle of the
cell
Anaphase Chromosomes (sister chromatids) are
pulled apart and move to the poles.
Telophase/Cytokinesis Occurs simultaneously Telophase
The nuclear envelope reforms around the chromosomes
The chromosomes uncoil Cytokinesis
The cytoplasm divides 2 daughter cells are produced (each are exact
copies of the original with 46 chromosomes)
What stages are these cells in?
Investigating Cell Reproduction Complete the lab activity
Paper lab
GO TO Meiosis PowerPoint
Regulating the Cell Cycle
Controls on Cell Division Cell growth and division can be turned on
and off Example
Cells in a petri dish will continue to grow until they come in contact with other cells.
A cut in the skin will cause cells to divide until the wound in healed.
Cell Cycle Regulators Cyclin
Protein that regulates the cell cycle in eukaryotic cells
When injected into a non-dividing cell it causes a mitotic spindle to form
Internal Regulators Responds to events inside the cell Makes sure that a cell does not enter mitosis
until all chromosomes are replicated
Cell Cycle Regulators (cont.) External Regulators
Respond to events outside the cell “Growth factors” that speed up or slow down
growth and division
Uncontrolled Cell Growth CANCER –
Cells that lose the ability to control cell growth Most cancers have damage to the p53 gene
Normally halts the cell cycle until all chromosomes are replicated
Chromosome damage builds up and the cancer cell loses the information that controls normal cell growth
Tumors masses of cells that can damage the surrounding tissue
CAUSES: smoking tobacco, radiation exposure (UV, XRAY, etc.), viral infection
Life Spans of Various Human CellsCell Type Life Span Cell DivisionLining of esophagus 2-3 days Can divide
Lining of small intestine
1-2 days Can divide
Lining of large intestine
6 days Can divide
Red blood cell Less than 120 days Cannot divide
White blood cell 10 hours to decades Cannot divide
Smooth muscle Long-lived Can divide
Cardiac (heart) muscle
Long-lived Cannot divide
Skeletal muscle Long-lived Cannot divide
Neuron (nerve cell) Long-lived Most do not divide
Life Spans of Human Cell Questions White blood cells help protect the body from
infection and disease-producing organisms. How might their function relate to their life span?
If cancer cells were added to the table, predict what would be written under the “Life Span” and “Cell Division” columns. Explain you’re the reasoning behind your predictions.