Post on 05-Oct-2020
Cell Structure and Function
Cells • Smallest living unit • Most are microscopic
Characteristics of All Cells
• A surrounding membrane • Protoplasm – cell contents in thick fluid • Organelles – structures for cell function • Control center with DNA
Cell Types
• Prokaryotic
• Eukaryotic
Prokaryotic Cells
• First cell type on earth • Cell type of Bacteria and Archaea
Prokaryotic Cells
• No membrane bound nucleus • Nucleoid = region of DNA concentration • Organelles not bound by membranes
Eukaryotic Cells • Nucleus bound by membrane • Include fungi, protists, plant,
and animal cells • Possess many organelles
Protozoan
Representative Animal Cell
Representative Plant Cell
Organelles • Tiny cell structures that are
specialized parts of a cell that have specific functions – a cell “organ.”
Plant Cell
Animal Cell
CELL MEMBRANE
• – “gate keeper” • outer boundary (or layer) of
the cell • controls the movement of
materials into and out of the cell
Cell Parts and Functions
Cell Membrane Protects the cell Lets things in and
out of the cell Location: around
the cell
Common features of all cells
1. Cell Membrane – selectively/differentially permeable (lets some things in and out)
CELL WALL
• found in plant cells • tough rigid boundary – made
of cellulose • gives cells their shape (it also
provides protection, as well as support)
Cell Wall Differences • Plants – mostly cellulose • Surrounds plasma membrane
CYTOPLASM
• – “cell fluid” • a gel-like material inside the
cell • Many cellular activities occur
here and where the organelles are contained
Cytoplasm • Viscous fluid containing organelles • components of cytoplasm
– Interconnected filaments & fibers – Fluid = cytosol – Organelles (not nucleus) – storage substances
Cell Parts and Functions
Cytoplasm Gel-like substances, holds
all Organelles in cell Location: in cell
NUCLEUS
– “brain of the cell” • controls cell processes • Contains DNA or chromosomes
- the heredity material or genetic blueprint of the cell
Nucleus
• Control center of cell
• Double membrane
• Contains – Chromosomes – Nucleolus
DNA
• Hereditary material
• Chromosomes – DNA – Protiens – Form for cell division
• Chromatin
NUCLEAR MEMBRANE
• – materials pass in and out through tiny holes called porins
Cell Parts and Functions
Nuclear Membrane Protects nucleus Lets things in/out of nucleus (pores) Location: around nucleus cell
NUCLEOLUS
• – ribosomes are made here
Cell Parts and Functions
Nucleolus (Nucleoli) Makes ribosomes Location: inside the nucleus (dark spot)
cell
Nucleolus
• Most cells have 2 or more • Directs synthesis of RNA • Forms ribosomes
CHLOROPLASTS
• – “energy processing organelles” • found only in plant cells • place where food is made for
plant cells
Chloroplasts
• Derived form photosynthetic bacteria • Solar energy capturing organelle
Cell Structures and Functions Chloroplast Traps suns energy
and Makes food Location: in plant
cells
MITOCHONDRIA
• – “powerhouse” • converts food (glucose) to
energy (ATP)
Cell Parts and Functions
Mitochondria Makes energy/ powerhouse Location: in cytoplasm
Mitochondria
• Break down fuel molecules (cellular respiration)
– Glucose – Fatty acids
• Release energy – ATP
RIBOSOMES
• – “protein factories” • place where protein is made in
the cells • some are attached – some float in the cytoplasm
Cell Parts and Functions
Ribosome Makes proteins Location: in cytoplasm or Attached to E.R.
ENDOPLASMIC RETICULUM
• – “conveyer belt” • transports synthesized proteins
throughout the cell
Cell Parts and Functions Endoplasmic Reticulum (E.R.) Transports materials and sends messages to all
parts of the cell Two types: smooth and rough (has ribosomes) Location: attaches from cell membrane to nuclear
membrane
Rough E.R.
Rough Endoplasmic Reticulum • Ribosomes attached to surface
– Manufacture protiens – Not all ribosomes attached to rough ER
• May modify proteins from ribosomes
Smooth Endoplasmic Reticulum
• No attached ribosomes • Has enzymes that help build molecules
– Carbohydrates – Lipids
GOLGI BODIES (Apparatus)
• sort, modify, process, and ship the proteins through the cell
• (Also known As GOLGI Apparatus)
Golgi Apparatus • Involved in synthesis of plant cell wall • Packaging & shipping station of cell
Cell Parts and Functions Golgi Bodies/Apparatus Packages and secretes (gets rid of) waste Location: in cytoplasm
GOLGI APPARATUS
VACUOLES • – “storage” • store water, sugar, salts,
nutrients, & wastes in cells • maintains the proper pressure
to provide structure and support in plant cells
Vacuoles
• Membrane bound storage sacs • More common in plants than animals • Contents
– Water – Food – wastes
Cell Parts and Functions
Vacuole Stores food and water Location: in cytoplasm
Vacuole
LYSOSOMES
• contain chemicals that break down waste materials.
Lysosomes • Contain digestive enzymes • Functions
– Aid in cell renewal – Break down old cell parts – Digests invaders
Cell Parts and Functions
Lysosome Contains digestive enzymes Destroys bacteria, old cell
parts… Location: in cytoplasm