Cell structures Flashcards
what are the macromolecules?
protein, DNA, Carbohydrates, Lipids
what are the type of cell?
prokaryotic cell and eukaryotic cell
- have no well defined nucleus and cell organelles
- smaller and simpler
- eubacteria, archaebacteria
Prokaryotic cell
- have nucleus and cell organelles
- more complex
- plants, animals, fungi, protists
eukaryotic cells
what are the cell theory?
- All plants and animals are composed of cells.
- Cell is the basic unit of life.
- All cells arise by reproduction from previous
cells
Elements that are found in the cell
C, H, O, N
what are the three regions of nucleus?
nuclear envelope
nucleolus
nucleoplasm
control center of the cell
Contains genetic material (DNA)
Nucleus
a. Barrier of the nucleus
b. Consists of a double membrane
c. Contains nuclear pores that allow for exchange of material with the rest of the cell
Nuclear envelope (membrane)
Sites of ribosome assembly
Ribosomes migrate into the cytoplasm through nuclear pores
Nucleolus
Perform certain functions such as supporting the chromatin material and nucleolus
Providing rigidity to the nucleus. It is the site of synthesis of DNA, RNA and ribosomal subunits
Nucleoplasm
Composed of DNA and protein
Present when the cell is not dividing
Scattered throughout the nucleus
Condenses to form chromosomes when
the cell divides
chromatin
Barrier for cell contents
Double phospholipid layer
Hydrophilic heads
Hydrophobic tails
Also contains proteins,
cholesterol, and glycoproteins
plasma membrane
- functions to support and suspend organelles and cellular molecules
Many cellular processes also occur in
Cytoplasm
Modifies, sort, and packages proteins
Produces different types of packages
Secretory vesicles
Cell membrane components
Golgi apparatus
Contain enzymes produced by ribosomes
Packaged by the Golgi apparatus
Digest worn-out or non-usable material
within the cell
Lysosomes
Membranous sacs of oxidase enzymes
▪ Detoxify harmful substances
such as alcohol and
formaldehyde
▪ Break down free radicals (highly
reactive chemicals)
Replicate by pinching in half
Peroxisomes
Network of protein structures that
extend throughout the cytoplasm
Provides the cell with an internal
framework
Three different types of elements
Microfilaments (thinnest)
Intermediate filaments
Microtubules (thickest)
cytoskeleton
three different types of cytoskeleton
microfilaments
intermediate filaments
microtubules
Rod-shaped bodies made up of
microtubules
Direct the formation of the mitotic
spindle during cell division
centrioles
The movement of substances into and out of the cell
Cell membranes are selectively permeable
(some substances can pass through, but others cannot)
membrane transport
what are the two methods of transport?
passive and active transport
- No energy is required
- Must have a concentration gradient
- Movement is from high concentration to low concentration
passive transport
- Cell must provide metabolic
energy (ATP) - Go against the concentration
gradient - From low concentration to high
concentration
active transport
Particles tend to distribute themselves evenly within a solution
Movement is from high concentration to low
concentration, or down a concentration gradient
diffusion
types of diffusion
simple diffusion, osmosis, facilitated diffusion, filtration
An unassisted process
Solutes are lipid-soluble
materials or small enough to
pass through membrane pores
simple diffusion
Highly polar water molecules
easily cross the plasma
membrane through aquaporins
osmosis
- Substances require a protein carrier
for passive transport - Transports lipid insoluble and large
substances
facilitated diffusion
- Water and solutes are forced through
a membrane by fluid, or hydrostatic
pressure - A pressure gradient must exist
- Solute-containing fluid is pushed from
a high-pressure area to a lower
pressure area
filtration
Substances are transported that are unable to
pass by diffusion
Substances may be too large
Substances may not be able to dissolve in
the fat core of the membrane
Substances may have to move against a
concentration gradient
ATP is used for transport
active transport
two common forms of active transport
active transport and vesicular transport
two types of vesicular transport
exocytosis and endocytosis
two types of endocytosis
phagocytosis and pinocytosis
Moves materials out of the cell
Material is carried in a membranous
vesicle
Vesicle migrates to plasma membrane
Vesicle combines with plasma
membrane
Material is emptied to the outside
exocytosis
Extracellular substances are engulfed
by being enclosed in a membranous
vesicle
endocytosis
cell eating: __________
cell drinking: __________
phagocytosis, pinocytosis