Transcript Aims - Excellence Gateway

Human Cell Biology
Organelle Structure and Function
Rachel Black
Chesterfield College
Topic
Organelle Structure and Function
Aims
 Basic overview to introduce Cell Organelles
Level
Level 3
Method
All PowerPoint slides introducing Cell Organelles, Human Cell Biology,
Levels of Organisation, Identify the Organelle, Nucleus, Endoplasmic
Reticulum, Ribosomes, Golgi Body, Lysosome, Mitochondria. Can be
shown as a slide show and students to take notes, or can be hand-outs for
the students.
Equipment




Laptop/Projector
Printer
Plain Paper
Printer
Duration
>30 Minutes
Human Cell Biology
• Lesson Objectives:
– Explain how the functions of the nucleus,
endoplasmic reticulum, ribosomes,
mitochondria, Golgi body and lysosomes are
linked to their structure.
Levels of Organisation
Body
Systems
Organs
Tissues
Cells
This is the level that we will be exploring
Identify the Organelle
Golgi Body
Cell
Membrane
(Plasma
Membrane)
Mitochondria
Nucleus
Lysosome
Rough ER
Cytosol
Ribosomes
Smooth ER
Nucleus
Structure
Function
• Bound by a double membrane (nuclear Controls substances entering and exiting
membrane or envelope)
the nucleus.
• Nuclear membrane has nuclear pores.
Allows the passage of large molecules out
of the nucleus.
• Contains the jelly-like nucleoplasm.
Contains chromatin (coils of DNA
bound to protein)
During cell division, chromatins condense
to form chromosomes (Contain DNA).
• Inside the nucleus is the round
nucleolus.
Manufactures RNA which is needed to
make ribosomes & proteins.
• Nucleus very prominent feature of the
cell. Usually 1 per cell.
Endoplasmic
Reticulum
Structure
Function
A system of hollow tubes and sacs,
created by folds of a double membrane.
Allows transport of materials within the
cell and between cells. Ensures proteins
are folded correctly.
The fluid filled spaces between the
membranes are called cisternae. These
cavities are connected.
Rough ER has ribosomes attached to its
outer surface.
Provides a large surface area for chemical
reactions.
Contains and transports proteins made by
ribosomes. Prevents proteins diffusing out
into cytosol.
Smooth ER has no ribosomes on its outer
surface.
Synthesis and transport of steroids &
lipids (fats)
Joined to the nuclear envelope.
Allows easy transport of RNA from the
nucleus to manufacture proteins in the
ribosomes.
Endoplasmic
Reticulum
Ribosomes
Structure
Function
Small & dense and present in great
numbers. Can be attached to rough ER or
free floating.
Site of protein synthesis.
DNA is a set of instructions for how to
make proteins.
Consists of a large and small subunit.
The nucleus sends out a copy of these
instructions as mRNA.
The ribosomes ‘read’ the mRNA, which
tells it what protein to make.
Ribosomes shape
and composition
Golgi Body
Structure
Function
Formed from rough ER ‘pinching off’ at
the sides to form vesicles which then fuse
together to form a tightly packed group of
flattened cavities.
Modifies chemicals to make them
functional. E.g. carbohydrates are added
to proteins to make glycoproteins such as
mucus when can then be secreted out of
the cell via vesicles.
It is constantly shifting, receiving vesicles
from the side nearest the nucleus (the
forming face) and loosing vesicles from
the side nearest the cell membrane (the
maturing face).
Secretes chemicals in tiny vesicles.
Forms lysosomes.
Golgi Body
Lysosome
Structure
Function
Small vacuoles formed from portions of
the Golgi body that have ‘pinched’ off.
Contain digestive enzymes called lytic
enzymes, which can destroy old and worn
out cell structures.
Membrane prevents digestive enzymes
leaking out and potentially destroying
vital cell components.
Digests material taken into the cell
e.g. white blood cells engulf bacteria and
the lytic enzymes in the lysosomes
destroy the harmful bacteria.
Mitochondria
Structure
Function
Oblong shaped.
Site of cellular respiration which is the
process of making ATP (energy) which
cells need to survive and function.
Has a double membrane. A smooth outer
membrane and a folded inner membrane.
The folds give a large surface area. These
folds create extensions called cristae.
Contains a fluid known as the matrix
which contains various chemical
compounds such as protein and lipids.
Has it’s own DNA so can control its own
protein synthesis.
Folds provide a large surface area for the
chemical reaction that produces ATP.