Ch. 7 Notes: Cell Biology. Sizes of living things

Ch. 7 Notes:Cell Biology

Sizes of living things

Early microscopists 1665 Robert Hooke (English) coined the

term "cell" while looking at cork. 1675 Anton van Leeuwenhoek (Dutch)

Lens maker who first reported observations of living cells which he called "animicules".

1831 Robert Brown (English) discovered the nucleus of the cell.

Three German scientists propose “The Cell Theory” in the 1800s

Matthias Schleiden - Botantist reported that all plants were composed of cells.

Theodor Schwann - Zoologist reported that all animals were composed of cells.

Rudolf Virchow – Physician reported that all cells came from pre-existing cells

Three parts of the cell theory

1. All living things are composed of cells.

2. Cells are the basic unit of structure and function of all living things.

3. New cells are produced from living cells.

Sizes Cells vary in size, but most are microscopic Can be unicellular or multicellular- Unicellular- one-celled organism. Very

versatile Multicellular- many celled organism. These

are more specialized with a division of labor.

Shape and function The shape and structure of a cell is closely

related to the function of the cell Most cells can generally-

Secure food for energy Remove waste Obtain oxygen Produce chemicals Regulate water balance Reproduce other cells

There are only two types of cells

Prokaryote Eukaryote

Prokaryote vs. Eukaryote Prokaryotes contain

no membrane bound structures. Circular chromosomes, cell walls made of peptidoglycen, smaller ribosomes, and fixed flagella

Eukaryotes contain membrane bound organelles. Linear chromosomes, cell walls made of cellulose of chitin, and flexible microtubule flagella or cillia.

Prokaryotic Cell

Prokaryote cell function and parts Cell wall-Protective out barrier Capsule- attachment to surfaces and protcetion Cytoplasm-water and nutrients that support the

structures inside the cell Flagellum- for swimming and movement Ribosome- for protein production Nucleoid- area where the DNA is located Mesosome

Only BACTERIA are considered prokaryotes.

Eukaryote Cell The eukaryotic cell contains Boundaries- for protection Organelles- for assembly, transportation,

and storage of cellular products, as well as cellular support, locomotion and reproduction.

Organelle-

Structures that perform a specific function in certain cells.

Some organelles have membranes, but eukaryotic cells are the only ones with organelles with membranes.

List of organelles: Nucleus, mitochondria, cell membrane,

lysosomes, chloroplast, ribosomes, golgi apparatus, smooth and rough endoplasmic reticulum, cytoplasm, vacuole, chloroplasts, centrioles, cell wall, nucleolus.

Differences in Eukaryote Cell

Plant Cell wall, plastids, central

water vacuole

Animal Centrioles, lysosomes

Boundaries of a Eukaryote Plasma Membrane (aka cell membrane)-

Surrounds the cell and controls what enters and leaves it.

Made of a phosopholipid bilayer with proteins embedded in it. This fluid mosaic structure allows for the membrane to be flexible

The cell is covered by an extracellular matrix made up of glycocalyx.

Cell wall- Aids in the protection and support of the cells Made in a series of steps

Middle lamella- a partition containing pectin Primary wall- cellulose added to the middle lamella. Flexible and can

stretch with the growing cell Secondary wall- cellulose and lignin added to the primary wall.

Inflexible

Fungus cell walls are made of chitin

The control-Cell nucleus Surrounded by a porous double bilipid membrane Controls the cells activities by regulating the building of

proteins, which in turn regulates the cell chemical processes and contains: DNA- master instructions for building proteins. Combines

with structural proteins to form chromatin, which is tightly coiled during cell division in the form of chromosomes

RNA- copy of the master instructions to be used in the actual building of a protein in the cytoplasm

Nucleolus- produces ribosomes (sites of protein synthesis)

Assembly, Transport, and Storage Protoplasm

Cytoplasm- jelly-like substance inside the cell membrane by outside the nucleus. Various organelles are suspended in it

Nucleoplasm- jelly-like substance inside the nucleus

Endoplasmic Reticulum A network of membranes of membranes

that form a series of channels throughout the cytoplasm. The cavity is used for storage, separation, and transport

Endoplasmic Reticulum Two Types

Rough and Smooth Rough ER- contains ribosomes attached to the

membranes. Important in the synthesis of proteins for export from the cell and for use in the cell membrane

Smooth ER- does not contain ribosomes. Used for synthesizing lipids.

Ribosomes Structures made up of protein and RNA

where proteins are assembled Ribosomes are located in two areas within

a cell Free- ribosomes that float in the cytoplasm and

all proteins made are directly used by the cell. Attached- bound to the rough endoplasmic

reticulum.

Golgi Apparatus Stacks of membrane used to modify, store,

and package proteins and lipids Proteins made in the endoplasmic reticulum

are transported and repackaged to be sent to another part of the cell or a new cell.

Vacuoles A membranous saclike structure used for

storage and excess water. In the plant cell it comprises a major portion

of the cell, but in animal cells, they are much smaller.

Lysosomes Membrane bound organelles formed by the

golgi apparatus and are used for breaking down large molecules within the cell by using digestive enzymes.

Energy Transformers Mitochondria and plastids are used by cells

to transform molecules into usable energy Mitochondria- double membrane. Used by the

cell to convert food energy into ATP Plastids- double membrane. Found in plants and

are used in storage and food production Chromoplast- plastids that contain pigment Leucoplast- plastids that store starch Cholorplast- convert solar energy into food energy

Energy Transformers Mitochondria

Chloroplast

Structural support and locomotion Cytoplasm support-

Microtubules- hollow-tube like. Make flagella, cytoskeleton, centrioles, cilia, spindle fibers

Microfilaments- solid rods. Make cytoskeleton and contract muscles.

Locomotion- Cilia-hair-like projections Flagella- tail-like projection used by whipping back and

forth Pili- hair-like projections

Centrioles, Centrosomes Centrioles- used during cellular division by the animal

cell Centrosome- used during cellular division by both

animal and plant cell. Plant cells however have no centrioles

Organelle Specialized structure that performs a

specific function in certain cells. Found in eukaryotes ONLY List of organelles:

Nucleus, mitochondria, cell membrane, lysosomes, chloroplast, ribosomes*, golgi apparatus, smooth and rough endoplasmic reticulum, cytoplasm, vacuole

Nucleus A membrane-covered

organelle that contains a cell’s genetic information (genes).

Not all living cells have nuclei.

Picture of a prokaryote

Eukaryotes do have membranes Eukaryotes have a nucleus. Their genetic

material is enclosed in a membrane-bound organelle.

Eukaryotes have membrane-bound organelles, including a nucleus.

If a cell has a nucleus, it is a eukayote;

Prokaryotes and eukaryotes Prokaryote: All bacteria are prokaryotes.

They have no nuclei. Eukaryotes: Animals, plants, protists (like

amoeba and algae), and fungi (yeast, mold, mushrooms, etc.) are all eukaryotes. They all have membrane-bound organelles.

Example of an animal cell: Eukaryotic cells Small vacuoles No cell walls Centrioles No photosynthetic organelles

Example of an animal cell

Example of a plant cell: Eukaryotic cells Large vacuoles Have cell walls No Centrioles Photosynthetic organelle = chloroplast

Plant cell anatomy

Your Turn Fill in the blanks for your copy of the plant

and animal cells and then make Make flashcards of the organelles

Eukaryotes: Have a nucleus. Animals, plants, protists

(like amoeba and algae), and fungi (yeast, mold, mushrooms, etc.) are all eukaryotes. They all have membrane-bound organelles.

Two types: Plant and animal cell Why is there a distinguished difference?

Example of an animal cell: Eukaryotic cells Small vacuoles No cell walls Centrioles No chloroplast

Example of a plant cell: Eukaryotic cells Large vacuoles Have cell walls No Centrioles Chloroplast

Prokaryote cells: nucleiod region, bacteria, no nucleus

Plant cells contain: cell wall, chloroplast, producers, photosynthesis, large central vacuole,

Living, ribosomes, cytoplasm, DNA, RNA, proteins

Cell wall

Animal cells: cell membrane, heterotrophs (consumers), motile,

Flagella, cilia, pilli

Golgi apparatus, r & s endoplasmic reticulum, lysosome, mitochondria, nucleolus, nucleus,