Cell Structure & Function Chapter 7- Cell Structure & Function

I. Life is Cellular A-The Discovery of the Cell It was not until the _________ that scientists began to use microscopes to observe organisms. In 1665 ____________used an early compound microscope to see tiny chambers in cork.He called these chambers cells after the tiny rooms in monasteries….we know these not to be empty now. Robert Hooke Mid-1600’s

About the same time in Holland________________used a single-lens microscope to look @ pond water, Anton van Leeuwenhoek

Cell Theory In 1838 Matthew Schleiden concluded plants were made of cells 1839 Theodore Schwann said all animals were made of cells 1855-Virchow said cells could only come from existing ones.

These 3 things compile_________________ Cell Theory All living things composed of ___________ Cells are the basic units of ___________________of living things New cells are produced from ______________________. Existing cells cells Structure and function

B-Exploring the Cell Florescent labels and light microscopy have been used to follow molecules through the cell. _________________,which scans cells w/a laser beam can make 3-d images of cells Video technology make it possible to watch cell growth , division and development Confocal light microscopy

Light makes it difficult to visualize tiny structures because it scatters/______________________allow things like proteins to be visualized (things as much as 1000 x smaller can be visualized….TEMS allow you to see specimens cut into ultra thin slices Electron microscopes

W/ a ______________specimens do not have to be cut to see 3-D images… W/ a ______________specimens do not have to be cut to see 3-D images….both must be placed into a vacuum so air molecules do not scatter electrons 1990’s-____________________________have revolutionalized visualization of surfaces and atoms have been observed…can be used in ordinary air and can show DNA structure Scanning probe microscopes SEM pollen

C .Prokaryotes and Eukaryotes Cells typically range from _________micrometers,but some bacteria are .2 and some amoeba are 1000 micrometers All cells have 2 things in common: cell membrane-a barrier @ some point they contain_______ 5-50 micrometers DNA

2 broad categories: _____________________________-genetic material is NOT contained in a nucleus/generally less complicated than other cells/carry out all cell activities…present day members are ________________. Prokaryotes bacteria

_____________________________-contain a nucleus w/ genetic material,generally larger,much diversity Eukaryotes

Working with a partner, answer the following questions. Division of Labor Section 7-2 A cell is made up of many parts with different functions that work together. Similarly, the parts of a computer work together to carry out different functions. Working with a partner, answer the following questions. 1. What are some of the different parts of a computer? What are the functions of these computer parts? 2. How do the functions of these computer parts correspond to the functions of certain cell parts? Go to Section:

Eukaryotes Prokaryotes Venn Diagrams Animal Cells Plant Cells Section 7-2 Eukaryotes Prokaryotes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell membrane Ribosomes Cell wall Animal Cells Plant Cells Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Lysosomes Go to Section:

II. EUKARYOTIC CELL STRUCTURE Organelles 2 major parts of eukaryotic cells nucleus cytoplasm Specialized structure that performs important functions within an eukaryotic cell. Cytoplasm is material inside membrane and outside nucleus

Plant Cell Smooth ER Vacuole (free) Cell Nucleolus Golgi apparatus Figure 7-5 Plant and Animal Cells Section 7-2 Nuclear envelope Ribosome (attached) (free) Smooth ER Nucleus Rough ER Nucleolus Golgi apparatus Mitochondrian Cell wall Cell Membrane Chloroplast Vacuole Plant Cell Go to Section:

Ribosome (free) Animal Cell Figure 7-5 Plant and Animal Cells Section 7-2 Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth Mitochondrian Cell Membrane Ribosome (free) (attached) Animal Cell Go to Section:

The Nucleus Contains nearly all the cell’s DNA Codes for instructions to make proteins and other molecules Surrounded by nuclear envelope---has many pores to allow material in and out Contains chromatin—has DNA bound to protein,usually spread throughout nucleus,but condenses during cell division to make CHROMOSOMES,containing genetic info Usually contain Nucleolus—assembly of ribosomes begin here.

Ribosomes Proteins are assembled here Made out of small particles of RNA and protein Found throughout cytoplasm Coded instructions from nucleus tell how to make proteins Cells active in protein synthesis have a lot of ribosomes

Endoplasmic Reticulum Site where lipid components of cell membrane are assembled,along w/ proteins and other materials exported from cell(those proteins are made there) Rough ER is involved in protein synthesis,because ribosomes are on it Newly made proteins leave ribosomes and insert on rough ER ,where they may be modified If cell makes a lot of protein ,there is much ER Smooth ER may contain many specialized enzymes

Lysosomes Small organelles filled w/enzymes May digest or break down lipids,carbs,and proteins into small molecules that can be used by the rest of the cell Lysosomes remove “junk”,or used up organelles….very important that this aspect function occurs

Vacuoles Sac like structures that store water ,salts ,proteins, and carbs Plants may have a single large water filled vacuole Contractile vacuoles control water in paramecium

Mitochondria and Chloroplasts Most all eukaryotic cells contain mitochondria that convert chemical energy stored in food into compounds convenient for cell to use Mitochondria have an outer and inner membranes In humans,nearly all mitochondria comes from ovum(egg cell)

Chloroplasts Capture energy from sunlight and convert into chemical energy in photosynthesis Contain 2 membranes and chlorophyll

Organelle DNA In chloroplasts and mitochondria Small DNA molecules Maybe descendants of early prokaryotes ----Endosymbiotic theory says these prokaryoic ancestors developed a symbiotic relationship w/ early eukaryotes and resided within---evolving into mitochondria

Cytoskeleton Network of protein filaments that help cell maintain shape Also involved in movement MICROFILAMENTS are threadlike structures made of a protein-actin….make a major network and a tough framework///allows amoebas and such to move MICROTUBULES-hallow structures made of proteins called tubulins—important in holding a cell’s shape----form a mitotic spindle in cell division/which helps separate chromosomes CENTRIOLES are microtubules near nucleus in animals and help organize cell division Microtubules also help make projections like cilia or flagella

Figure 7-7 Cytoskeleton Cell membrane Endoplasmic reticulum Section 7-2 Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Michondrion Go to Section: