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Unit: Cells
Sections: Cell Theory, Structure of Life, Cellular Respiration, Photosynthesis
Key Words:
Cell
Cell theory
Virus
Cytosol
Prokaryote
Asexual reproduction
Cellular
differentiation
Biotechnology
Eukaryotic
DNA
System
Tissue
organelle
Cellular respiration
photosynthesis
Essential Questions: (by section)
Cell Theory
-
Why are cells important?
How are new cells formed?
How do cells in single-celled and multi-cellular organisms differ?
What are the main characteristics of cells?
Structure of Life
-
What are cells and why are they important?
What structures do most cells have in common?
How do animal cells and plant cells differ?
How do cells in unicellular and multicellular organisms differ?
Cellular Respiration
-
Why is cellular respiration important?
What are the reactants and products of cellular respiration?
What is cellular respiration?
Photosynthesis
-
What is photosynthesis?
Where does photosynthesis occur?
Cell Theory
Robert Hooke – 1665 – English scientist


Looked at cork under microscope
Found it made up of empty boxes – coined the term “cells”

https://www.emaze.com/@AICWTWOQ/Cell-Theory
Matthias Schledian – 1830s – German scientist


studied plant parts
realized they were made up of cells

Theodor Schwann – German scientist
 Studied animal cells
 Realized they were made up of cells
https://www.emaze.com/@AQTTRQI/Cell-Theory-

http://www.ssplprints.com/image/101417/schwann-theodor-plant-andanimal-cells-1839
Together they were theorizing all living things were comprised of cells
Rudolf Virchow – German doctor
 Hypothesized that new cells derive from already existing cells
Theory today:
-
Cells are the most basic unit of life
All organisms consist of one or more cells
All cells come from pre-existing cells
Unicellular (single celled) vs. Multicellular
Prokaryotic
(single-celled)
Eukaryotic
(multi-celled)
Structure of life
•single-celled organisms
•no membrane around DNA (no nucleus)
•most have cell wall
•go through fission (reproduction) - identical copy
•ex. Bacteria cells
•multi-celled organisms
•have distinct membranes around organelles
•has a nucleus
•more complex organisms
•membrane around DNA
•goes through mitosis (reproduction) - identical copy of DNA
Eukaryotic Cells – cell organelles & functions
-
Cytoplasm – gel material, allows for nutrient transport and cushions organelles
Cell membrane – protective outer covering of cell, double layer, allows molecules to pass in and out
Cell nucleus – “brain” of the cell, where genetic material (DNA) is found
Ribosome – Protein generators of the cell
Mitochondria – “powerhouse” of the cell, where cellular respiration occurs
Vacuole/Vesicle – storage organelle, in plants is the largest (stores water – turgor pressure - and other
nutrients)
Golgi bodies – External “UPS” system, packages materials for transport out of the cell
Lysosomes – “Lysol” of the cell, helps break down older worn out parts
Cell wall – in plant cells only, rigid structure, helps with plant form
Endoplasmic Reticulum (ER) – Internal “UPS” system, packages materials for transport within the cell
Chloroplasts – “solar collectors” that contain chlorophyll (green pigment) to help with photosynthesis
Chart – www.docstoc.com
Synthesis of
chemicals
necessary for
life
Respiration
Excretion of
wastes
Nutrition
Movement
Specialized cells for Eukaryotes:
Regulation
and response
to stimuli
Growth
Cell
Processes
Reproduction
blood
cells
fat cells
bone
cells (red,
white,
and
platelets)
nerve cell
(neuron)
skin cell
skeletal
muscle
cells
smooth
muscle
cells
Cellular Respiration
Cellular process
-
Energy is stored (potential) in the bonds of food substances
Converts that chemical potential energy to KE that the cell can use for life processes
Most of the reaction occurs in the MITOCHONDRIA
ATP – adenosine triphosphate
o High-energy compound that is used by cells to function
Carbs, fats, & proteins used as fuel
Chemical Reaction:
C6H12O6 + O2  CO2 + H2O
Glucose + Oxygen  Carbon Dioxide + Water
-
Also known as “aerobic” respiration (requires oxygen)
3 parts of the process
o Glycolysis
 Occurs in the cytosol
 Does not require O2
 Produces “pyruvate” and small amounts of ATP
 Converts “pyruvate” into lactic acid or alcohol (also known as fermentation)
o Krebs cycle
 Occurs in the mitochondria
 O2 extracts remaining energy from “pyruvate”
 About 16x more CPE released with O2 than in glycolysis alone
o Phosphorylation
 Occurs in the mitochondrial membrane
Photosynthesis
Basis of food chain – where energy begins – transfer of energy
SUN!!!
o Supplies the necessary energy and is converted by producers
o Stores energy in forms of chemical bonds of sugar molecules (ex. Glucose)
o Phytoplankton, photosynthetic organisms harness sun’s energy
 process is inefficient
 energy is “lost” to the environment
 constant input of energy is necessary
 use green pigment (chlorophyll)
Sun releases
radiant energy
collected by
photosynthetic
organisms
stores some of the
energy collected
in bonds of sugar
molecules
Chemical reaction:
CO2 + H2O + light  C6H12O6 + O2
Carbon dioxide + water + light  glucose + oxygen