Cell Structure and Function 1665 Robert Hooke coined the term “cells” 1830 Schleiden and Schwann All living things are composed of cells Cell is the basic unit of life Cell Theory 1850s Virchow All cells come from pre-existing cells 1668 Anton Van Leeuwenhoek

What are some general characteristics of all cells? 1. Plasma membrane 2. Genetic information (DNA) 3. Chemical reactions 4. Cytoplasm- all material inside the P.M. and outside the nucleus which includes water, salts, and organic molecules. (Some cell’s cytoplasm includes organelles).

What are the two major types of cells? 1. Prokaryotic cells (no nucleus) 2. Eukaryotic cells (have a nucleus) Archaea- prokaryotes such as those that live in extreme habitats Bacteria- Strep, Staph, and Cyanobacteria “Protists”, Fungi, Plants, and Animals

Eukaryotic Cell (Animal Cell)

A. Nucleus The control center of the cell Nucleolus – is where ribosomes are made Chromatin - DNA and Protein What does a nucleus contain?

B. Ribososmes Sites of protein synthesis The proteins made here will function as enzymes within the cytosol 1.Free Ribosomes- Two Types of Ribosomes 2. Bound Ribosomes- Attached to Rough ER The proteins made here will become lysosome enzymes, membrane proteins, or secretory proteins

C. Endoplasmic Reticulum Network of membranes forming interlocking channels Involved in protein synthesis, membrane production, and transporting. 1.Rough ER (contains ribosomes) Two Types of ER The proteins made here will become lysosome enzymes, membrane proteins, or secretory proteins

Endoplasmic Reticulum Involved in lipid and carbohydrate synthesis In the liver it helps detoxify drugs. 2. Smooth ER Two Types of ER

Endoplasmic Reticulum

D. Golgi Complex Stacks of flat membrane sacks The cell’s warehouse or Post Office Stores, modifies, packages, and distribute molecules Vesicles – are small sacks of membrane

Golgi Complex (The Cell’s Distribution Center)

Flow of protein within cell Name a protein that you want to build.

Remember it starts with DNA Nucleus Nucleus DNA RNA Protein Rough ER Golgi Complex Plasma Membrane Vesicle Vesicle

E. Lysosomes serve as the cell’s digestive system Lysosomes are vesicles that contain digestive enzymes Function: digest individual molecules such as proteins, fats, and carbohydrates as well as complete microorganisms and defective organelles. What are some examples of how lysosomes are used?

The Cell’s Powerhouse F. Mitochondria are these oval, round, or tubular organelles made from a double membrane system. Sites of aerobic respiration Inner and outer membrane Cristae- formed from folding of inner membrane Matrix- inner space that contains enzymes that break down food molecules

Mitochondrion (The Cell’s Powerhouse)

The Cell’s Organizer The Cytoskeleton is a 3-D network of 3 different protein filaments that is responsible for the shape, internal organization, and movement of a cell. The 3 types of filaments Microtubules- guide vesicles through the cell and help form cilia and flagella. VIDEO VIDEO Microfilaments - help Amoeba and WBCs crawl and cause muscle cells to contract VIDEO VIDEO Intermediate filaments- networks of these filaments help determine a cell’s shape

Locomotion

Immune Response showing macrophages in action

How are plant cells different? Cell wall Central vacuole Chloroplasts

A Plant Cell is a Eukaryotic Cell

Thylakoids contain chlorophyll which traps light energy Chloroplasts are plastids that contain the green pigment chlorophyll and are the sites of photosynthesis. Stroma is the fluid filled space w/in the chloroplast where CO 2 is converted into glucose Internal structure of chloroplasts

Chloroplast

Other plastids include: Amyloplasts- stores starch Chromoplasts- synthesize and retain yellow, orange, or red pigments

Vacuoles Animal cells have vacuoles that are mainly used for storage of food and are often temporary. Plant cells have large central vacuoles that may occupy 50-90% of the cell interior.

Functions of the central vacuole Maintain the cell’s water balance Storage: pigments, ions, proteins, and poisons for defense Turgor pressure- the pressure of the water w/in the CV pushes the cytoplasm against the cell wall. Disposal of metabolic waste (toxins)

Central Vacuole