Week 1 1
FUNCTIONS & STRUCTURE OF ORGANELLES
Controls what enters/leave cells
Protection and support
Rough endoplasmic reticulum (RER):
Mostly flattened sacs (cisternae) with ribosomes
Continuous with SER and nucleus
Makes/modifies/ships proteins to the Golgi
Adds carbohydrates to proteins to make
glycoproteins (part of the glycocalyx)
Smooth endoplasmic reticulum (SER):
Tubes with no ribosomes
Continuous with RER
Makes lipids (including steroids and
Detoxifies alcohol and drugs
Stack of cisternae with no ribosomes
Modifies, sorts, ships proteins (produced by bound ribosomes) to their final destinations
o Destinations such as outside the cell, in the cell membrane, and inside membrane-bound
Small vesicle with digestive enzymes
Breakdown of bacteria, viruses, and toxins brought in via
Breakdown of old organelles to release stored molecules
Self-destruction of injured or dying cells (autolysis) Week 1 2
Inner membrane highly folded
Makes ATP through cellular
Continuous with RER
Controls protein synthesis + metabolism
Membrane-bound sacs that stores, imports, and exports materials such as food particles, solids, or
CHARACTERISTICS OF LIFE
1. Exchanges materials with their environment
2. Obtains energy from organic molecules
3. Synthesize complex organic molecules
5. Responds to stimuli
LEVELS OF STRUCTURAL ORGANIZATIONS
Function: Provides the site where information from the DNA is used to make proteins.
Free ribosomes Bound ribosomes
Float in cytoplasm Attached to membranes of the ER
Produces proteins used immediately in Produces three groups of proteins:
the cytosol o Proteins exported outside the cell
o Cell membrane proteins
o Membranous organelle proteins Week 1 3
Nucleus houses DNA, the information required to make proteins.
By determining which proteins are made, the nucleus regulates all cellular activities.
Most cells have one nucleus.
Larger cells may have several nuclei, such as skeletal muscle cells.
Red blood cells have no nucleus.
Double membrane with pores
Regulates what material may enter or exit the nucleus
When a cell prepares to divide, chromatin in the nucleus coils and condenses to form short rod-like
structures called chromosomes.
Carries the genetic material that is carried from one generation to the next.
One or two darker regions inside the nucleus
Produces the basic subunits of ribosomes, which are then transferred to the cytoplasm for assembly.
Cell metabolism is the sum total of all the chemical processes inside the cell.
Anabolic reactions Catabolic reactions
Building up processes Breaking down processes
Simpler building block molecules are used Complex molecules are broken down into
to make complex molecules simpler molecules
Energy is used Energy is released
i.e., starch made from glucose subunits i.e., glucose gets broken down
CELLULAR GROWTH PROCESSES
3. Differentiation (specialization) – development of specific and distinctive features in cells
COMMON CHEMICAL ELEMENTS IN THE HUMAN BODY
*Oxygen (O): *Hydrogen (H):
65% of body mass, major component of 9.5%, constituent of water and most
inorganic (water, 2 ) and organic organic molecules
molecules Influences acidity of body f