Chapter 7 Notes: Cells Name__________________Date_________ Period___

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 Discovered in the 1990’s Produces images by tracing the surfaces of samples with a fine probe Can observe single atoms in the air or in solution

Eukaryotic Cells 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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7–1 Life Is CellularA. The Discovery of the Cell

1. Early Microscopes2. The Cell Theory

B. Exploring the CellC. Prokaryotes and Eukaryotes

1.Prokaryotes2. Eukaryotes

DNA

Plasma membrane

Cell wall

Ribosomes

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.

Two Basic Cell TypesProkaryotic 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.

A Prokaryotic Cell

Plasma membrane

Nucleus

Nucleolus

Chromosomes

Organelles

A Eukaryotic Cell

7–2 Eukaryotic Cell StructureA. Comparing the Cell to a FactoryB. NucleusC. RibosomesD. Endoplasmic ReticulumE. Golgi ApparatusF. LysosomesG. VacuolesH. Mitochondria and Chloroplast

1. Mitochondria2. Chloroplasts

3. Organelle DNAI. Cytoskeleton

7.2 Eukaryotic Cell StructureOrganelles 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 proteinsRibosomes 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 reticulumEndoplasmic 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 detoxificationGolgi 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) Paramecium have a contractile vacuole that pumps excess water out of the cell, which aids with homeostasisMitochondria Mitochondria are membrane-bound organelles in plant and animal cells that transform ___________ for the cell.

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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 productionChloroplasts 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 plantOrganelle 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 ________________ cellsCilia 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.

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Plant and Animal Cell Microscope LabPurpose :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 bodyepithelial cells- cells that make up tissues that cover bodies or organs

Plant cells have structures not found in animal cells Cell wall - help give plants shape, support and protection Chloroplast-site of photosynthesis Large central vacuole - contains water which helps keep plant from

wilting; when the vacuole is full it presses against the cell wall to give the plants rigidity (turgid pressure)

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

Plant Cells Animal CellsShape Rectangular CircularComponents Cell wall Cell Membrane Cell Membrane Nucleus

Nucleus

Animal Cell

Plant Cell

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The Structure of the Cell Membrane Lipids (lipid bilayer) Proteins embedded in _________________

o Some proteins form channels or pumps to move material across the membrane Carbohydrates attached to proteins

o These act as signals or identification cards, allowing the cells to recognize each other Because it allows different components to move through it, it is also called the “fluid mosaic model”The Plasma Membrane All living cells must maintain a balance regardless of internal and external conditions. Survival depends on the cell’s

ability to maintain the proper conditions within itself. The plasma membrane is the _____________________ between the cell and its environment.

It is the plasma membrane’s job to: allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions

are. remove excess amounts of these nutrients when levels get so high that they are harmful. allow waste and other products to ______________ the cell.Cell membrane This process of maintaining the cell’s environment is called homeostasis. Semi- (selectively) permeability is a process used to maintain homeostasis in which the plasma membrane allows some

molecules into the cell while keeping others out.Diffusion

The process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.

Molecules move through cell boundaries Concentration- the amount of solute in a given amount of solution Equilibrium- when the concentration of a solute is the _________ throughout the

solution Does _______ require energy; moves down the concentration gradient (HàL) Moves oxygen, carbon dioxide and water

Osmosis diffusion of ___________ through a selectively permeable membrane

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Outside of cell

Inside of cell (cytoplasm)

Cell membraneProteins

Proteinchannel Lipid bilayer

Carbohydrate chains

Cell Membrane All cells are surrounded by the ______________________ It regulates what enters and leaves the cell and provides protection and

support It protects against viral and bacterial ________________

7.3: Cellular Boundaries The cell membrane acts as a __________-permeable membrane.Cell Wall The cell wall is a fairly ________ structure located outside the plasma

membrane that provides additional support and protection. It is present in plants, algae, fungi, and many prokaryotes. Allows water oxygen, carbon dioxide to pass through easily Plant cell walls are made of cellulose (fiber)

7–3 Cell Boundaries A. Cell Membrane B. Cell Walls C. Diffusion Through Cell Boundaries

1. Measuring Concentration2. Diffusion

D. Osmosis 1. How Osmosis Works 2. Osmotic Pressure E. Facilitated Diffusion F. Active Transport

1. Molecular Transport2. Endocytosis and Exocytosis

It consists of two layers called the lipid bilayer.

The cell membrane is also called the plasma membrane

Facilitated Diffusion movement of specific molecules across cell membranes through protein

channels passive - does not require an input of energy always moves particles down a concentration gradient (HàL) because these molecules are polar they must travel through channels in

transport proteins; ex: glucose

Hypotonic Solution concentration of solutes is _____________ than the concentration inside the cell causes water to diffuse into the cell animal cells may burst in a hypotonic solution plant (and many bacteria) cells do not burst because they are surrounded by a rigid cell wall

Active Transport energy-requiring process that moves material across a cell membrane against a concentration difference requires energy from _______ molecules can move particles up a concentration gradient (from low to high) requires carrier proteins to “pump” particles across membrane ex: Na-K pumps in nerve cells, movement of nutrients into plant roots

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The graph to the right shows the relative size of molecules that move in and out of the cell

Isotonic Solution the concentration of solutes equals the concentration of solutes inside the cell does not result in the net diffusion of water into or out of the cell kidneys and skin help to maintain isotonic conditions in your body

Hypertonic Solution concentration of solutes in solution is _______ than the concentration of solutes inside the cell causes water to diffuse out of the cell; may cause cell to shrivel and shrink; disrupts

metabolism and may kill cell

HighConcentration

LowConcentration

CellMembrane

Glucosemolecules

Proteinchannel

Bulk transport large molecules, food, and other substances are packaged

in membrane-bound sacs and moved across the membrane

Requires _____________ Endocytosis

o Phagocytosiso Pinocytosis

Excoytosis

Endocytosis process by which a cell takes material _______ the cell by infolding of the cell

membrane

Two Typeso Phagocytosis (cell eating) -process in which extensions of cytoplasm surround and engulf large particles and

take them into the cell  o Pinocytosis (cell drinking) -process by which a cell takes in a _______ from the surrounding environment

Exocytosis wastes and cell products leave the cell by fusing with membrane products packaged by Golgi apparatus and excreted from cell Removal of ___________ by the contractile vacuole of paramecium.

Cell Specialization Cells throughout an organism can develop in different ways to perform different tasksAnimal 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

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Muscle cell Smooth muscle tissue Stomach Digestive system

7–4 The Diversity of Cellular Life A. Unicellular Organisms B. Multicellular Organisms

1. Specialized Animal Cells2. Specialized Plant Cells

C. Levels of Organization1. Tissues2. Organs

3. Organ Systems

7.4- Diversity of Cellular LifeUnicellular Organisms Sometimes _____________ cells are the organism Grow, respond to the environment, transform energy, and reproduceMulticellular Organisms Made up of many cells Very ________________ Depend on communication and cooperation between specialized cells