Download Cell Structure and Function Eukaryotic Cell: Neuron

Cell Structure and Function
Eukaryotic Cell: Neuron
Cell Structure and
Function
Eukaryotic
Cells- Red
Blood Cells
Prokaryotic CellsBacteria
Prokaryotes- NO NUCLEUS!
Eukaryotes= Have a Nucleus!
Cell Structure and Function
-All living organisms are made of cells.
-A cell is a small, membrane enclosed structure
filled with an aqueous solution where
organelles and other subcellular structures are
found. “subunit of life!”
-Cells are of different size and shape
-The cell’s size and shape can be related to its
specific function.
From Prokaryotes to Eukaryotes
• It is thought that all organisms living now on
Earth are derived from a single cell born 3,500
millions of years (my) ago – Primordial Cell
-Simple organic molecules likely formed billions
of years ago
Unicellular vs. Multicellular Organisms
• Why unicellular?
• Why multicellular?
Can we see Cells?
• Some cells
We are able to
See without a
Microscope
Ex/ chicken egg,
Egg yolk
Structural Features of cellsOutside Covers
All cells have a plasma or cell membrane, which
contains the cell
Plant cells and most
bacteria have an
outermost additional
layer, the plant cell
wall and the bacterial
cell wall respectively
Outside Cell Covers
The plant cell wall is the outermost layer of
plant cells
• It provides extra protection to the plant
Why do plants need these extra features?
• Cell walls of adjacent plant cells are in close
communication
Inner Structures of the Cell
The nucleus of eukaryotic cells is contained by the
nuclear envelope.
Inside the nucleus contains chromatin (DNA + DNA
associated proteins) and a nucleolus
Nucleolus: In the nucleus, makes ribosomes and
nucleic acids found within the nucleus.
Inner structure: Nucleus
Controls all cell
activities
-
-Hold all genetic
information (DNA)
-”Brain of the cell”
Some cells lose their nucleus as they
mature Ex/ RBC’s
Inner Structures
• Ribosomes: Make proteins!
– Assembled by their instructions of DNA
REVIEWWhat is a protein?
Inside Structures: Cytoplasm
• Defined as the clear gelatinous fluid inside of a
cell.
– Holds all of the organelles of the cell.
– Multiple chemical reactions take place here.
– Kept out of
nucleus by
nuclear envelope.
Inside Structures: ER
• Endoplasmic Reticulum: Proteins are made
here
A folded membrane found in the cytoplasm of a
cell that provides a large
surface area on which
chemical reactions can easily
take place.
Inside Structures: ER
Rough ER: Makes proteins
Smooth: makes lipids, processing of sugars, and
detoxification of drugs and Poisons
-One of cell’s delivery
systems
Inside Structures: Golgi Apparatus
• Golgi Apparatus: Closely stacked, flattened
membrane sacs that receives newly made
proteins and lipids from the ER
-distributes them to the plasma membrane
and other organelles throughout the cell.
Inside Structures: Vacuole
• Vacuole: Stores food, enzymes, and other
materials needed by a cell.
– A small percentage of vacuoles store waste
products.
– Vacuoles in plants cells are huge!
• Usually only one.
– Animal cells can have many small vacuoles.
Inside Structures: Lysosomes
• Lysosomes: Contain digestive enzymes.
- They digest excess or worn out organelles, food
particles, and engulfed viruses or bacteria
– Their membrane prevents harmful enzymes from
pouring into the cytoplasm of the cell.
Inside Structures: Mitochondria
• Mitochondria: Organelles in which food
molecules are broken down (glucose) to
produce energy.
– Shaped like tiny sausages.
– Have their own DNA/Ribosomes
– Inner membrane forms long, narrow folds called
cristae.
Inside Structures: Mitochondria
Inside Structures: Chloroplasts
• Chloroplasts: Photosynthesis takes place here
• Transforms light energy into chemicals to
produce food
• In plants only!
Inside Structures: Chloroplasts
• Chlorophyll: A green pigment that traps the energy
from sunlight and gives plants their green color.
• It is found in the thylakoid membrane of the
chloroplast.
• **What gives plants their green color**
Inside Structures: Centriole
• Helps in cell reproduction
• Helps in cell division
Structures for Support
• Cytoskeleton: A network of thin, fibrous
elements that provide support for organelles
and helps the cell maintain its shape.
– Microtubules: Thin, hollow cylinders of protein.
– Microfilaments: Thin, solid protein fibers.
– Both work together to provide support.
Structures for Movement
• Cillia: Hair-like projections” that beat together
to create movement
• Flagella: Long projections that move in a whiplike motion to produce movement.
– The major method of locomotion in unicellular
organisms.
Cillia
Flagella