cell structure and functiongithensjaguarsteam.weebly.com/.../parts_of_cells_-_.pdf · 2018. 9....

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