Download Chapter 7 Notes: Cells

Chapter 7 Notes: Cells
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7–1
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Life Is Cellular
A. The Discovery of the Cell
1. Early Microscopes
2. The Cell Theory
B. Exploring the Cell
C. Prokaryotes and Eukaryotes
1. Prokaryotes
2. Eukaryotes
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7.1: The History of the Cell Theory
Before microscopes were invented, people believed that diseases were caused by
curses and supernatural spirits.
As scientists began using microscopes, they quickly realized they were entering a
new world–one of ___________________________.
______________________ enabled scientists to view and study cells, the basic
units of living organisms.
Development of Light Microscopes
The first person to record looking at water under a microscope was Anton van ______________________.
The microscope van Leeuwenhoek used is considered a simple light microscope because it contained one lens and used
natural light to view objects.
Compound light microscopes use a series of lenses to magnify objects in steps.
These microscopes can magnify objects up to _________ times.
The Cell Theory
Robert ____________ was an English scientist who lived at the same time as van Leeuwenhoek.
Hooke used a compound light microscope to study cork, the dead cells of oak bark.
He thought the structures he observed resembled the one room “cells”
Hooke is credited with giving _________ their name
_________ are the basic building blocks of all living things.
The cell theory is made up of three main ideas:
All organisms are composed of _____ or more cells.
The cell is the basic unit of ____________________________________ of organisms.
All cells come from _________________________ cells.
Three Scientists contributed to the Cell Theory:
1838- Schleiden: ____________ are made of cells
1939- __________________: animals are made of cells
1855- Virchow: New cells are produced from the division of _______ cells
Development of Electron Microscopes
The ___________________ microscope was invented in the 1940s.
This microscope uses a beam of electrons to magnify structures up to 500,000 times their actual size.
There are two basic types of electron microscopes.
o The scanning electron microscope scans the _____________ of cells to learn their three dimensional shape.
o The transmission electron microscope allows scientists to study the structures contained within a cell.
Scanning Probe Microscope
Plasma
Discovered in the 1990’s
membrane
Produces images by tracing the surfaces of samples with a fine probe
Ribosomes
DNA
Can observe single atoms in the air or in solution
Two Basic Cell Types
Prokaryotic Cells
 Cells that ________ contain internal membrane-bound
structures and do not have a _______________ are
called prokaryotic cells.
 _________ organisms such as bacteria are very simple.
 They still carry out all of life’s activities such as
respiration, cell reproduction, growth, etc.
Cell wall
Eukaryotic Cells
A Prokaryotic Cell
 Cells containing membrane-bound structures and a _________ are called eukaryotic cells.
 Most of the multi-cellular plants and animals are made up of cells that are very ______________________ and diverse
in their structures and functions
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7–2 Eukaryotic Cell Structure
A. Comparing the Cell to a Factory
B. Nucleus
C. Ribosomes
D. Endoplasmic Reticulum
E. Golgi Apparatus
F. Lysosomes
G. Vacuoles
H. Mitochondria and Chloroplast
1. Mitochondria
2. Chloroplasts
3. Organelle DNA
I. Cytoskeleton
A Eukaryotic Cell
Nucleus
Nucleolus
Chromosomes
Plasma membrane
7.2 Eukaryotic Cell Structure
Organelles
Organelles
 The membrane-bound structures within _____________________ cells are called organelles.
 Each “little organ” has a specific _________________ that contributes to cell survival.
 Separation of organelles into distinct compartments benefits the eukaryotic cells.
Biologists divide the cell into two major parts
 The nucleus is the central membrane-bound organelle that manages cellular functions.
 Everything between the cell membrane and the nucleus is called the ________________.
Nucleus
 Nuclear envelope – double layered membrane surrounding _____________; contains small pores
 Nuclear pores- allow ___________________ of materials in and out of nucleus
 Chromatin-granular material visible within the nucleus; consists of _____ tightly coiled around proteins
 Chromosomes – threadlike structure within the nucleus containing the genetic information that is passed from one generation
of cells to the next (chromosomes are formed when chromatin condenses during cell division)
 Nucleolus – dense material in nucleus; makes ___________________ which make proteins
Ribosomes
 Ribosomes are made in the ____________________.
 They travel in and out of the nucleus through the nuclear pores.
 Ribosomes are small particles within the cell on which proteins are assembled; made of RNA and protein
 They can be free (in the cytoplasm)
 They are also attached to the ____________ endoplasm reticulum
Endoplasmic reticulum
 The endoplasmic reticulum (ER) is responsible for assembly, transport, and storage of molecules within cell.
 There are two types
 Rough ER- contains ribosomes and makes ________________
 Smooth ER- lacks ribosomes; has enzymes that make membrane _______ and detoxifies drugs
 _____________ cells contain many smooth ER for detoxification
Golgi Apparatus
 Stacks of membranes in the cell that modifies, sorts, and _______________ proteins from the
endoplasmic reticulum
 The Golgi apparatus is like a customization shop where finishing touches are added to proteins.
Lysosomes
 Lysosomes are organelles that contain digestive ______________. They digest excess or worn out organelles, food particles,
and engulfed viruses or bacteria.
 The lysosomes are the _________________ crew of the cell
 Tay-Sachs disease is caused by excess lipid accumulation on the brain. The cause of this disease has been traced to
lysosomes that failed to function properly
Vacuoles
 Vacuoles are membrane-bound spaces used for temporary storage of __________________ (such as water, salts, proteins,
and carbohydrates)
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 Paramecium have a contractile vacuole that pumps excess water out of the cell, which aids with homeostasis
Mitochondria
 Mitochondria are membrane-bound organelles in plant and animal cells that transform ___________ for the cell.
 A mitochondria, like the endoplasmic reticulum, has a highly folded inner membrane.
 The folds increase the surface area of the mitochondrion in order to make more energy (_____)
 Cellular Respiration takes place in the mitochondria of cells
 Cellular respiration is the process that converts chemical energy stored in food into ATP energy for cells to use.
 _______________ cells (needed for movement) contain a large number of mitochondria for energy production
Chloroplasts
 Chloroplasts are found in cells of plants and some other organisms
 ________________ are organelles that capture light energy and produce food to store for a later time.
 Photosynthesis takes place in the chloroplasts
 Chloroplasts contain green pigment called ______________________.
 Chlorophyll traps light energy and gives leaves and stems their green color.
 Chloroplasts acts like a ____________ power plant
Organelle DNA
 Lynn Margulis - described mitochondria and chloroplasts as free-living aerobic prokaryotes which developed a
partnership with host cell; endosymbiosis hypothesis
 chloroplasts and mitochondria have their own circular DNA & ribosomes, make their own proteins, reproduce on their
own
Cytoskeleton
 Cells have a ________________ structure called the cytoskeleton within the cytoplasm.
 It is a network of proteins that help maintain cellular shape and movement
 The cytoskeleton is composed of microtubules and microfilaments.
 Microtubules are thin, hollow cylinders made of protein that maintain cell ____________
 Microfilaments are thin solid protein fibers that help cells move (amoeba)
Centrioles
 Made of microtubules and cytoskeleton
 One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope
 Help to organize cell division (helps cells split into two)
 Only found in ________________ cells
Cilia and Flagella
 Some cell surfaces have cilia and flagella, which are structures aid in locomotion or feeding.
 Made of microtubules from the cytoskeleton
 Cilia and flagella can be distinguished by their structure and by the nature of their action.
 ___________ are short, numerous, hair-like projections that move in a wavelike motion.
 _________________ are long projections that move in a whip-like motion.
 Flagella and cilia are the major means of locomotion in unicellular organisms.
Plant and Animal Cell Microscope Lab
Purpose :
To compare the basic structures and shape of plant and animals cells by looking at onion (epidermal) cells and cheek
(epithelial) cells
epidermal cells- cells that make up the protective outer covering of plants; tissue that covers the human body
epithelial cells- cells that make up tissues that cover bodies or organs
To review basic microscope parts and lab techniques like staining cells and preparing a wet mount for microscope slides
Plant cells have structures not found in animal cells
 Cell wall - help give plants shape, support and protection
Plant Cells
Animal Cells
 Chloroplast-site of photosynthesis
Shape
Rectangular
Circular
 Large central vacuole - contains water which helps keep plant from
Components Cell wall
Cell Membrane
wilting; when the vacuole is full it presses against the cell wall to
Cell Membrane Nucleus
give the plants rigidity (turgid pressure)
Nucleus
Animal cells have structures not found in plant cells
 Cytoskeleton- animal cells use the cytoskeleton to help with support
and aid in movement
 Centrioles-aid in cell division
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Plant Cell
Animal Cell
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7–4 The Diversity of Cellular Life
A. Unicellular Organisms
B. Multicellular Organisms
1. Specialized Animal Cells
2. Specialized Plant Cells
C. Levels of Organization
1. Tissues
2. Organs
3. Organ Systems
7.4- Diversity of Cellular Life
Unicellular Organisms
 Sometimes _____________ cells are the organism
 Grow, respond to the environment, transform energy, and reproduce
Multicellular Organisms
 Made up of many cells
 Very ________________
 Depend on communication and cooperation between specialized cells
Cell Specialization
 Cells throughout an organism can develop in different ways to perform different tasks
Animal cells
 Red Blood Cells- carries _______________; small and round to fit through vessels
 Pancreatic Cells- produce enzymes to break down food; contains many ribosomes and rough ER to aid in this process
 Muscle Cells- long and threadlike to aid in movement; contain many _____________________ for energy production
Plant Cells
 Guard cells- in the pores of leaves; aids in _______________ exchange
Levels of Organization
 Many multicellular organisms have structures called _______ that have a specific function and work with other organs.
 Working together, these organs carry out the life processes of the entire organism.
 Multicellular organisms contains cells, tissues, organs and organ systems
Muscle cell
Smooth muscle tissue
Stomach
Digestive system
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