Chapter 4 Cell Processes and Energy
How does the sun supply living things with the energy they need?What happens during the process of photosynthesis?
Section 1: Photosynthesis
Chapter 4 Cell Processes and Energy
Sources of Energy
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis.
Chapter 4 Cell Processes and Energy
Autotroph vs. Heterotroph
Autotroph: any organism that makes its own food using the energy of the sunlight captured by photosynthesis
Examples: plants, green algae
Heterotroph: an organism that can not make its own food, so it must consume another organism for energy
Examples: animals, fungi, most bacteria
95% of all living organisms are heterotrophs.
Both autotrophs and heterotrophs get their energy from the sun. Autotrophs get their energy DIRECTLY from the sun, while heterotrophs get their energy INDIRECTLY.
Chapter 4 Cell Processes and Energy
The Two Stages of Photosynthesis
During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars.
Chapter 4 Cell Processes and Energy
The Photosynthesis Equation
Chapter 4 Cell Processes and Energy
Breaking Down the Photosynthesis Equation
Products: C6H12O6 + 6 O2
CCCCCC OO OO HHHHHH OO OO HHHHHH OO OO
OOOOOO
________________________
6 Carbons +
12 Hydrogens + 18 Oxygens
Products: C6H12O6 + 6 O2
CCCCCC OO OO HHHHHH OO OO HHHHHH OO OO
OOOOOO
________________________
6 Carbons +
12 Hydrogens + 18 Oxygens
Raw Materials: 6 CO2 + 6 H2O
COO COO HHO HHOCOO COO HHO HHOCOO COO HHO HHO________________________
6 Carbons +
12 Hydrogens + 18 Oxygens
Raw Materials: 6 CO2 + 6 H2O
COO COO HHO HHOCOO COO HHO HHOCOO COO HHO HHO________________________
6 Carbons +
12 Hydrogens + 18 Oxygens
Chapter 4 Cell Processes and Energy
End of Section: Photosynthesis
Chapter 4 Cell Processes and Energy
• What events occur during cellular respiration?• What is fermentation?
Section 2: Cellular Respiration
Chapter 4 Cell Processes and Energy
Two Stages of Cellular Respiration
Cellular Respiration: A process where cells break down simple food molecules such as sugar and release the energy they contain.
Chapter 4 Cell Processes and Energy
The Cellular Respiration Equation
Chapter 4 Cell Processes and Energy
Photosynthesis and Respiration
You can think of photosynthesis and cellular respiration as opposite processes.
Chapter 4 Cell Processes and Energy
Fermentation
Fermentation: A process that provides cells with energy without using oxygen.
• Alcoholic Fermentation: Occurs in yeast and other one-celled organisms. This is the process used to make yeast turn grape juice into wine.
• Lactic Acid Fermentation: Occurs in humans and other animals when they exercise and there is a lack of oxygen. This leads the acid taste in your mouth and sore muscles.
Chapter 4 Cell Processes and Energy
End of Section: Respiration
Chapter 4 Cell Processes and Energy
What events take place during the three states of the cell cycle?How does the structure of DNA help account for the way in which DNA copies itself?
Section 3: Cell Division
Chapter 4 Cell Processes and Energy
The Cell Cycle
Cell Cycle: The regular sequence of growth and division that cells undergo.
Made up of 3 stages:• Stage 1: Interphase• Stage 2: Mitosis• Stage 3: Cytokinesis
Chapter 4 Cell Processes and Energy
Interphase
Cells spend most of their time in this phase.
During Interphase, the following 5 events will occur:• The cell will perform its “normal” functions and
duties.• The cell will grow to about twice it's original size.• The cell's organelles will make copies of
themselves and double in quantity.• The cell's DNA will make a copy of itself right
before Mitosis begins.• Once the DNA is copied, the cell will make
structures that it will use to help divide itself.
Chapter 4 Cell Processes and Energy
Mitosis
During mitosis, the cell’s nucleus divides into two new nuclei. One copy of the DNA is distributed into each of the two daughter cells.
Chapter 4 Cell Processes and Energy
Mitosis
Four stages in Mitosis:
• Prophase
• Metaphase
• Anaphase
• Telophase
Chapter 4 Cell Processes and Energy
Mitosis: Prophase
“Chromatin” winds up into a condensed shape called “chromatid”.
Chromatin: unwound DNA
Chromatid: wound DNA
Chapter 4 Cell Processes and Energy
Mitosis: Prophase
The cell gets ready for the “Tug of War” activity that occurs in Mitosis.
Chapter 4 Cell Processes and Energy
Mitosis: Prophase
The cell gets ready for the “Tug of War” activity that occurs in Mitosis.
The pair of centrioles move to opposite sides of the nucleus.
Spindle fibers (the “ropes”) form between the centrioles.
The nuclear envelope that surrounds the nucleus breaks down.
Chapter 4 Cell Processes and Energy
Mitosis: Metaphase
The chromatids line up on the equator of the cell.
Chapter 4 Cell Processes and Energy
Mitosis: Anaphase
The chromatids separate and move to opposite sides of the cell.
The cell starts to stretch apart as it gets ready for Cytokinesis.
Chapter 4 Cell Processes and Energy
Mitosis: Telophase
Chromatids unwind and return to their string-like chromatin shape.
2 new nuclear envelopes form to make 2 new nuclei.
Chapter 4 Cell Processes and Energy
Cytokinesis
Must finish after Mitosis or else the cell will split into 2 cells before the DNA is evenly divided.
The 2 new cells are called “daughter cells”.
Each daughter cell is identical to the original parent cell.
Chapter 4 Cell Processes and Energy
The Cell Cycle
Chapter 4 Cell Processes and Energy
D.N.A.
D.N.A. stands for
Deoxyribonucleic Acid.
D.N.A. is the “instruction
manual” or “blueprint” of
all living things.
Chapter 4 Cell Processes and Energy
D.N.A.
A single strand of D.N.A. in each cell is about 6 feet long. Multiplied by all the cells in your body, you have enough D.N.A. to go to the Sun and back about 70 times (the Sun is 93 million miles away).
Chapter 4 Cell Processes and Energy
D.N.A.
D.N.A.'s unique shape was discovered by James Watson and Francis Crick in 1953, with help from Maurice Wilkins and Rosalind Franklin.
Chapter 4 Cell Processes and Energy
D.N.A.
D.N.A. has a double helix structure, which resembles a spiral staircase.
Chapter 4 Cell Processes and Energy
D.N.A.
The sides of the twisted D.N.A. ladder are made up of a sugar called deoxyribose. In between the deoxyribose sugars is a molecule called phosphate.
Chapter 4 Cell Processes and Energy
D.N.A.
The rungs (steps) of the D.N.A. ladder is where we find
the “blueprint” information. These rungs are made up of
only 4 types of nitrogen bases:
• Thymine (T)• Adenine (A)
• Guanine (G)• Cytosine (C)
Chapter 4 Cell Processes and Energy
D.N.A.
Each rung of the D.N.A. ladder is made up of a pair of nitrogen bases.
Adenine (A) only pairs up with Thymine (T).Guanine (G) only pairs up with Cytosine (C).
Chapter 4 Cell Processes and Energy
D.N.A.
D.N.A. is able to make copies of itself by “unzipping”
and filling in the blanks with matching bases.
Chapter 4 Cell Processes and Energy
Structure of DNA
The DNA molecule, supported by proteins, is shaped like a twisted ladder.
Chapter 4 Cell Processes and Energy
Replication of DNA
Because of the way in which the nitrogen bases pair with one another, the order of the bases in each new DNA molecule exactly matches the order in the original DNA molecule.
Chapter 4 Cell Processes and Energy
End of Section:
Cell Division
Chapter 4 Cell Processes and Energy
What is differentiation?What factors influence how and when cells differentiate within different organisms?
Section 4: Cell Differentiation
Chapter 4 Cell Processes and Energy
Specialized Cells
Plants have undifferentiated cells in their stems and roots that can give rise to different kinds of cells.
Undifferentiated plant cell
Leaf cell
Transport cell
Root cell
Chapter 4 Cell Processes and Energy
End of Section:Cell Differentiation