HONORS BIOLOGY

CHAPTER 7

Cell Structure and Function

A. SCIENTISTS AND THE CELL

THEORY

1. ROBERT HOOKE (1665) Before 1600’s fiber/tissue = basic unit

of life Observed cork cells Coined the term “cell”

2. VAN LEEUWENHOEK (1683) Made

improvements to the microscope

First to see living cells

“animalcules” unicellular organisms

THE CELL THOERY

3. Mathias Schleiden (1838)4. Theodor Schwann

(1838)

Plants- made of cells Animals- made of cells

5. RUDOLPH VIRCHOW (1855) Cells come from other cells

THE CELL THEORY 1. All living

things are made of cells

2. All cells come from preexisting cells

3. Cells are the basic units of structure and function

Possible b/c of development of the microscope

Involved many of scientists over hundreds of years.

B. MICROSCOPES

LIGHT MICROSCOPY

LIGHT MICROSCOPY

ELECTRON MICROSCOPY

MICROGRAPH OF A NEURON AND DENDRITES USING ANTIBODIES, FLUORESCENT PROTEINS

AND CONFOCAL MICROSCOPE

C. TYPES OF CELLS

Prokaryote vs. Eukaryote

TWO CELL TYPES

Prokaryote Eukaryote

No Nucleus No organelles Simple structure Small, unicellular Bacteria

Nucleus Membrane bound

organelles Complex structures Animals, plants,

fungi, protists

PROKARYOTIC

EUKARYOTIC PLANT EUKARYOTIC ANIMAL

D. CELL STRUCTURE

Lysosome Leucoplasts Chromoplasts Mitochondria Chloroplast Cytoskeleton Centrioles Cilia Flagella

Plasma Membrane

Cell Wall Nucleus Cytoplasm Ribosomes Rough ER Smooth ER Golgi Body Vacuole

PLASMA MEMBRANE Phospholipid bilayer embedded with

protein “Fluid Mosaic” theory Regulates movement of molecules into

or out of the cell

CELL WALL Rigid structure

outside of the plasma membrane

Protects and supports cell

Plants, fungi, bacteria

Made of cellulose

NUCLEUS Control center for the cell Chromatin

DNA “blueprint” for cell’s proteins Nucleolus

Makes ribisomes

CYTOPLASM Liquid inside the cell Water/nutrients Contains

organelles

E. ASSEMBLY, STORAGE, AND

TRANSPORT

RIBOSOMES Site of protein synthesis

ENDOPLASMIC RETICULUM

Produces and transports molecules

GOLGI BODY Stores, modifies and packages proteins,

hormones etc. Post office of the cell

VACUOLE Stores food, waste, sugar, water etc. Storage center of the cell

LYSOSOME Digests food molecules or worn-out cell

parts

LEUCOPLASTS Store starch (in plants)

CHROMOPLASTS

Contain pigments (in plants)

ENERGY TRANSFORMATI

ONS

MITOCHONDRIA “Powerhouse of the cell” Site of cellular respiration

CHOLOROPLASTS Site of photosynthesis

SUPPORT AND LOCOMOTION

CYTOSKELETON Internal

framework of the cell

Microtubules- provide support

Microfilaments- enable cells to move (contractile proteins)

CENTRIOLES Aid in the division of animal cells

CYTOSKELETON

LOCOMOTION Cilia-short- fibers

Flagella- long fibers

CELLULAR TRANSPORT

Molecules constantly enter and leave the cell

PASSIVE TRANSPORT Requires no energy Examples:

Diffusion and OsmosisFacilitated Diffusion

Transport proteins in membrane moves sugar, amino acids etc

Follows concentration gradient

FACILITATED DIFFUSION

DIFFUSION Movement of molecules from high

concentration to low concentration Passive transport- requires no energy

OSMOSIS Diffusion of water through a selectively

permeable membrane

ISOTONIC SOLUTION Concentration of

solutes are equal inside and outside of the cell.

HYPERTONIC VS. HYPOTONIC

Solution outside the cell has a higher concentration of solutes than the cell.

Less water inside

Solution outside the cell has a lower concentration of solutes than the cell.

More water inside

HYPERTONIC VS. HYPOTONIC

TURGOR PRESSURE

Wilting = loss of turgor pressure

CELL PRESSURE

Plasmolysis Cytolysis Shrivel Burst

ACTIVE TRANSPORT Carrier proteins – transport molecules

Low concentration to High concentrationUses energy

ENDOCYTOSIS “into” the cell Engulfs material by enclosing it in

membrane Forms a vacuole within the cell

EXOCYTOSIS Expelling large amounts of material

from the cell

ACTIVE AND PASSIVE TRANSPORT

https://www.youtube.com/watch?v=kfy92hdaAH0&list=PL978360DC8EE52FCB

VOYAGE INSIDE THE CELL https://

www.youtube.com/watch?v=Ao9cVhwPg84