The CELL Flashcards
It is the smallest unit that is capable of
performing life functions.
cell
● The structural and functional unit of all
living organism
cell
The building block of life
cell
Vital functions of an organism occur within
cells
All cells contain _______ information
necessary for regulating cell functions and for transmitting necessary information to the next cell generation
hereditary
EXAMPLES OF CELLS
Amoeba
Nerve cell
RBC
WBC
Plant stem
Bacteria
TWO TYPES OF CELLS
Prokaryotic
Eukaryotic
- Do not have structures surrounded
by membranes - Few internal structures
- One-celled organisms
- bacteria, archae
PROKARYOTIC
- Contain organelles surrounded by
membranes - Most living organisms
- multicellular organisms such as
plants and animal cell
EUKARYOTIC
T or F| cell membrane is present in both prokaryotes and eukaryotes
TRUE
Has no definite nucleus; DNA is present but not separate from the rest of the cell
prokaryotes
Do prokaryotes have mitochondria?
NO - enzymes for oxidation reactions located on plasma membrane
Do prokaryotes have Endoplasmic Reticulum?
NO
Do both prokaryotes and eukaryotes have ribosome?
YES
Do prokaryotes and eukaryotes have chloroplasts?
Prokaryotes don’t have it. It photosynthesis is present it is located in chromatophores
Eukaryotes only have it in plant cells
CELL STRUCTURE
- Plasma membrane
- Cytoplasm: cytosol + organelles
- Nucleus
- Outer membrane of cell that controls
movement in and out of the cell - Double layer
- Phospholipid bilayer
- Proteins (integral and peripheral)
- Cholesterol
- Attached carbohydrates (glycolipids and
glycoproteins)
PLASMA/CELL MEMBRANE
- Barrier between inside and outside of cell
- Controls entry of materials: transport
- Receives chemical and mechanical
signals - Transmits signals between Intra and extracellular spaces
PLASMA/CELL MEMBRANE
THREE TYPES OF CELL JUNCTIONS
Gap Junction
Desmosome
Tight Junction
- When two cells are right next to
each other, their cell membranes
may actually be touching
GAP JUNCTION
- They physically connect cells like the
gap junction, but no opening is created
DESMOSOME
- Happens when two membranes
actually bond into one
TIGHT JUNCTION
- Fluid within cells: 2/3 of total
Intracellular (ICF)
Fluid…
* Between cells =
* In blood vessels =
* In lymphatic vessels =
Extracellular (ECF)
Interstitial
Plasma
Lymphatic
- The liquid doing the dissolving (usually
water)
Solvent
- the dissolved material (particles or
gas)
Solute
- Amount of solute in a given amount of
solvent
Concentration
- Difference in concentration between 2
areas of solution
Concentration gradient
TWO TYPES OF TRANSPORT
ACTIVE
PASSIVE
- Diffusion (simple and facilitated)
- Osmosis
PASSIVE
- Endocytosis
- Exocytosis
ACTIVE
the process by which molecules spread from areas of high concentration, to areas of low concentration
PASSIVE TRANSPORT: SIMPLE DIFFUSION
SIMPLE DIFFUSION: When the molecules are even throughout a space - it is called
equilibrium
is the passage of molecules or ions across a biological membrane through specific transport proteins and requires no energy input
FACILITATED DIFFUSION
Requires a carrier in membrane but not ATP
FACILITATED DIFFUSION
Solute goes down concentration gradient
FACILITATED DIFFUSION
Maximum transport speed depends on number of carriers
insulin increases number of
carriers for glucose in
plasma membrane
FACILITATED DIFFUSION
Diffusion of water across selectively
permeable membrane
OSMOSIS
Types of solutions surrounding human RBCs
Isotonic
Hypotonic
Hypertonic
solution outside RBC has same concentration of solute as RBC:
0.9% NaCl
Isotonic
solution outside of RBC has lower concentration: 0% NaCl → hemolysis
Hypotonic
solution outside of RBC has higher concentration: 4% NaCl→crenation
Hypertonic
RBC in Isotonic Solution
NORMAL
RBC in Hypotonic Solution
HEMOLYSIS
RBC in Hypertonic Solution
CRENATION
RULE FOR OSMOSIS: If the area outside the cell has more salt–then water will be sucked out of the cell
SALT SUCKS
Where salt is…
water will follow
- Requires a carrier (called a pump) and
energy (ATP)
ACTIVE TRANSPORT
- Can transport up a concentration gradient from an area of lower concentration to an area of higher concentration
- Critical for moving important ions
ACTIVE TRANSPORT
Major active transport in most cells is
Na+ or K+ pump
Reabsorption of glucose, amino acids and salts by the proximal convoluted tubule of the nephron in the kidney
ACTIVE TRANSPORT
Taking “in” large molecules by the cell
- importing materials into cell
ENDOCYTOSIS
2 types of ENDOCYTOSIS
Phagocytosis
Pinocytosis
________, process by which certain living cells called phagocytes ingest or engulf other cells or particles.
Phagocytosis
________ refers to the uptake of extracellular fluids and dissolved solutes, such as fat droplets, vitamins, and antigens.
Pinocytosis
- Removing large particles (waste) from the cell
- Exporting materials out of the cell
EXOCYTOSIS
moves with the gradient
high to low concentration
no cellular energy expenditure required
no protein help needed
Passive Transport
moves with the gradient
high to low concentration
no cellular energy expenditure required
proteins help: serves as gates
Facilitated Transport
moves against the gradient
low to high concentration
cellular energy input required
proteins serve as pumps
Active Transport
CELL ORGANELLES
- Cytoplasm
- Nucleus, nucleolus, nuclear envelope
- Mitochondrion
- Endoplasmic reticulum
- Golgi apparatus
- Vesicles, e.g. lysosome
- Cytoskeleton
- Flagella and cilia
- Centrioles
- is the fluid that fills a cell
- Cell contents
- Gel-like mixture
- Surrounded by cell membrane
- Contains hereditary material
- Includes organelles and cytosol
- Excludes nucleus
CYTOPLASM
- Directs cell activities
- Separated from cytoplasm by nuclear
membrane - Round or oval structure surrounded by
nuclear envelope with nuclear pores - Contains nucleolus
- Store genetic material (DNA) in genes
arranged in 46 chromosomes
NUCLEUS
makes ribosomes that pass into cytoplasm through nuclear pores
nucleolus
Store genetic material (DNA) in genes
arranged in ___ chromosomes
46
contains information for directing
protein synthesis
DNA
- is the suspension fluid that holds the cell’s chromatin and nucleolus
- It is not always present in the nucleus
- When the cell divides, the nuclear membrane dissolves and the nucleoplasm is released. After the cell nucleus has reformed, the nucleoplasm fills the space again
NUCLEOPLASM
- Surrounds nucleus
- Made of two layers
- Openings allow material to enter and leave nucleus
NUCLEAR MEMBRANE OR ENVELOPE
- Inside nucleus
- Contains RNA to build proteins
NUCLEOLUS
Sausage-shaped with many folded
membranes (______) and liquid matrix
containing enzymes
MITOCHONDRIA
cristae
Have some DNA, ribosomes (can make
proteins)
MITOCHONDRIA
Nutrient energy is released and trapped
in ATP; so known as “power houses of
cell”
MITOCHONDRIA
Produces energy through chemical
reactions – breaking down fats &
carbohydrates
MITOCHONDRIA
Controls level of water and other materials in cell
MITOCHONDRIA
Recycles and decomposes proteins, fats,
and carbohydrates
MITOCHONDRIA
Structure: network of folded membranes
ENDOPLASMIC RETICULUM
Functions: synthesis, intracellular
transport
ENDOPLASMIC RETICULUM
The double membranes of smooth and
rough ER form sacs called _______
cisternae
Two types of ER
Rough ER
Smooth ER
ER - studded with
ribosomes (sites of protein
synthesis)
Rough ER
ER - lacks ribosomes
Smooth ER
Functions:
- lipid synthesis
- release of glucose in liver cells into bloodstream
- drug detoxification (especially in liver cells)
- storage and release of Ca2+ in muscle
cells (where smooth E.R. is known as
sarcoplasmic reticulum or SR)
ENDOPLASMIC RETICULUM
- Made within the nucleus (in nucleolus)
- Sites of protein synthesis
- Consist of ribosomal RNA (rRNA) +
proteins - Contain large and small subunits
- Can be attached to endoplasmic reticulum or free in cytosol
RIBOSOMES
- Protein ‘packaging plant‘
GOLGI COMPLEX
GOLGI COMPLEX: was named after ________, an Italian biologist
Camillo Golgi
Structure: Flattened membranes
(cisternae) with bulging edges (like stacks of pita bread)
GOLGI COMPLEX
Functions: gathers simple molecules and
combines them to make molecules that are more complex
GOLGI COMPLEX
- Move materials within and out of
the cell - Modify proteins à glycoproteins
and lipoproteins that: - Become parts of plasma
membranes, Are stored in
lysosomes (cell digestion machines) or are exported by exocytosis
GOLGI COMPLEX
Contains digestive enzymes
LYSOSOME
Digestive ‘plant’ for proteins, fats, and
carbohydrates
LYSOSOME
Help in final processes of digestion within cells
LYSOSOME
Carry out _____ (destruction
of worn out parts of cell) and
_____ (death of old cells)
LYSOSOME
- autophagy
- autolysis
hereditary disorder; one missing lysosomal enzyme leads to nerve destruction
Tay-Sachs
SMALL BODIES
Peroxisomes
Proteasomes
o hold on to enzymes that require
oxygen (oxidative enzymes)
o break down fatty acids, digest
alcohol and protect cells against
hydrogen peroxide
o detoxify; abundant in liver
Peroxisomes
o digest unneeded or faulty protein
(proteolysis)
o Faulty proteins accumulate in brain
cells in persons with Parkinson or
Alzheimer disease
Proteasomes
- Maintains shape of cell
- Positions organelles
- Changes cell shape
CYTOSKELETON
CYTOSKELETON Includes:
microfilaments
intermediate filaments
microtubules
- is a small set of microtubules arranged in a specific way
CENTRIOLES
are found in pairs and move towards the poles (opposite ends) of the nucleus when it is time for cell division
CENTRIOLES
Structure:
o Two centrioles arranged
perpendicular to each other
o Composed of microtubules: 9
clusters of 3 (triplets)
o Pericentriolar material: Composed
of tubulin that grows the mitotic
spindle
CENTROSOME
Function: moves chromosomes to ends
of cell during cell division
CENTROSOME
Specialized for motion
CILIA AND FLAGELLA
o single tail like structure on sperm
o Propels sperm forward in reproductive tract
Flagellum
o in groups
o Found in respiratory system:
move mucus
Cilia
