HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
Movement through Cell Membrane
CELL
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Basic unit of life
Synthesis of molecules
Communication
Cell metabolism and energy release
Reproduction and inheritance (DNA)
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Cell membrane selectively determines what
can pass in and out of the cell.
Enzymes, glycogen, and potassium are in in
higher concentrations INSIDE the cell.
Sodium, calcium, and chloride are found in
higher concentrations OUTSIDE the cell.
Cell Structure
Ways molecules Pass through Cell Membrane
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Organelles
- specialized structures in cells that
perform specific functions.
- Ex: Nucleus, mitochondria, ribosomes,
etc.
Cytoplasm
- jelly-like
substance
that
holds
organelles.
1. Directly through (diffusion):
- Oz and CO2 (Small molecules)
2. Membrane channels:
- Proteins that extend from one side of
the cell membrane to other.
- Size, shape, and charge (+/-) determine
what can go through
- Ex: Na+ passes through Na+ channels
Cell Membrane
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Outermost component a cell
Function: selective barrier and
cytoplasm
Extracellular: material outside cell
Intracellular: material inside cell
encloses
Structure of Cell Membrane
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Called Fluid Mosaic Model
Made of phospholipids and proteins
Phospholipids form a double layer or bilayer
Phospholipids contain 2 regions: polar and
nonpolar
3. Carrier molecules:
- Bind to molecules, transport them
across, and drop them off.
- Ex: glucose
4. Vesicles:
- Can transport a variety of materials
- Fuse with cell membrane
Polar regions
- “heads”
- Hydrophilic (H2O loving)
- exposed to H2O
Nonpolar regions
- “tails”
- hydrophobic (H2O fearing)
- away from H2O
Trans By: Katherine Mae C. Dela Cruz
Page 1 of 5
HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
Diffusion
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Movement of molecules from areas of high to
low concentration.
Solvent: substance such as H2O that solute
is being added to.
Solute: substance added to solvent that
dissolves.
Solution: solid, liquid, or gas that contains
one or more solutes.
Ex: Add salt to H2O → H2O = solvent, salt =
solute, mixture = solution.
Osmosis
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Diffusion of water across a cell membrane
Osmotic pressure: force required to prevent
movement of water across cell membrane.
Concentration gradient:
- Measures conc. Difference at 2 points
- Greater the distance the faster the
solute will travel.
Filtration:
- Movement of fluid through a partition
with holes.
Types of Osmotic Solutions
Mediated Transport Mechanisms
1. Facilitated diffusion:
- Diffusion with aid of a carrier molecule
- Requires no ATP
2. Active transport:
- Moves substances from low to high
conc.
- Ex: Sodium-potassium pump
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Trans By: Katherine Mae C. Dela Cruz
Hypotonic solution
- lower conc. of solutes outside cell
- higher conc. of H2O outside cell
- H2O moves into cell
- Lysis (burst)
Hypertonic solution:
- higher conc. of solutes outside cell
- higher conc. H2O moves out
- crenation (shrinks)
Isotonic solution
- equal conc. of solutes
- water doesn’t move
- cell remains intact
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HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
Endocytosis
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Process that brings materials into cell using
vesicles.
2 types
- Phagocytosis → cell eating (solid
particles)
- Pinocytosis → cell drinking (liquid
particles)
Exocytosis
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Process that carries materials out of cell
using vesicles.
Trans By: Katherine Mae C. Dela Cruz
Page 3 of 5
HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
ORGANELLES
1. Cytoplasm
LOCATION
FUNCTION
CHARACTERISTIC
Inside cell
Give cell shape and hold
organelles in place
Houses DNA
Jelly-like fluid
2. Nucleus
Center of the cell
3. Nuclear envelope
Edge of nucleus
Separates the contents
of the nucleus from the
cytoplasm and provides
the structural framework
of the nucleus
Where materials pass in
and out of nucleus
4. Nuclear pores
Surface of nucleus
5. Chromosome
Inside nucleus
6. Chromatin
Inside nucleus
7. Nucleolus
In nucleus
Produce ribosomes
8. Ribosome
Attached to RER or
cytoplasm
Cytoplasm
Produce proteins
9. RER (Rough
Endoplasmic
Reticulum)
10. SER (Smooth
Endoplasmic
Reticulum)
11. Golgi apparatus
Part of genetic makeup
All cells contain nucleus at
some point
double membrane composed
of an outer and an inner
phospholipid bilayer
fully permeable to small
molecules up to the size of
the smallest proteins.
Made of DNA and proteins
Loosely coiled chromosomes
It has no limiting membrane. It
does not hold any
chromosomes
half protein and half rRNA
Site of protein synthesis
Membranes with ribosomes
attached
Cytoplasm
Site of lipid synthesis
(Ex: cholesterol)
Membranes with ribosomes
Cytoplasm
Collect, sort, package,
and distribute proteins,
and lipids
Distributes materials out
of cell
Closely, packed stacks of
membranes
12. Secretory vesicle
Cytoplasm
13. Lysosome
Cytoplasm
14. Mitochondria
Cytoplasm
15. Cilia
Cell surface
16. Flagella
17. Microvilli
Enzymes that digest
foreign material
Produces ATP
membrane-enclosed sacs
that store and transport
substances to and from one
cell to another and from one
part of a cell to another
destroy invading viruses and
bacteria.
Contains folds (cristae)
Many per cell
Cell surface
Move materials across
cell’s surface
Move cell (Ex: sperm)
Cell surface
Increase surface area
Shorter than cilia
Trans By: Katherine Mae C. Dela Cruz
1 per cell
Page 4 of 5
HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
Cytoskeleton
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Cell’s framework
Made of proteins
Function: provide support
Hold organelles in place
Enable cell to change shape
DNA (Deoxyribonucleic Acid)
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Double helix in nucleus
Composed of nucleotides
Contains 5 carbon sugar (deoxyribose,
nitrogen base, phosphate)
Types of Cytoskeleton
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Microtubules
- Largest diameter
- Provide structural support
- Form cilia and flagella
Intermediate filaments
- Medium diameter
- Maintain cell shape
Microfilaments
- Smallest diameter
- Involved in cell movement
Flow of Genetic Information
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Also called Central Dogma
Occurs in three stages
- DNA replication
- Transcription
- Translation
DNA Replication
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Whole Cell Activity
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A cell’s characteristics are determined by the
type of proteins produced.
Proteins’ function is determined by genetics.
Information in DNA provides the cell with a
code for its cellular processes.
Trans By: Katherine Mae C. Dela Cruz
Page 5 of 5
HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
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Gene Expression
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Anticodons: 3 nucleotide bases carried by
tRNA
Information in DNA directs protein synthesis
Proteins provide code for gene expression
Enzymes regulate chemical reactions
Uses transcription and translation
Cell Division
Transcription
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Process by which DNA is “read”
Occurs in ribosomes
Produces mRNA (messenger RNA)
mRNA contains codons
codons: set of nucleotide bases that code for
a particular amino acid.
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Formation of 2 daughter cells from a single
parent cell.
Uses mitosis and meiosis
Each cell (except sperm and egg) contains
46 chromosomes (diploid)
Sperm and egg contains 23 chromosomes
Mitosis
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Cell division that occurs in all cells except sex
cells
Form 2 daughter cells
Components of Mitosis
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Chromatid
- 2 strands of chromosomes that are
genetically identical
Centromere
- Where 2 chromatids are connected
Centrioles
- Small organelles composed of 9 triplets
Translation
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Process by mRNA is converted into amino
acid (polypeptides)
Produces proteins
Codons pair with anticodons
Trans By: Katherine Mae C. Dela Cruz
Page 6 of 5
HUMAN ANATOMY AND PHYSIOLOGY
NU MANILA
LECTURE: Cell Structures and Their Functions
DATE OF LECTURE: 05/09/2022
TEACHER: Elaine Anne L. Tandoc
Stages of Mitosis
1. Interphase
- Time between cell divisions
- DNA is in strands (chromatin)
- DNA replication occurs
2. Prophase
- Chromatin
condenses
into
chromosomes
- Centrioles move to opposite ends
3. Metaphase
- Chromosomes align
4. Anaphase
- Chromatids separate to form 2 sets of
chromosomes
- Chromosomes move towards centrioles
5. Telophase
- Chromosomes disperse
- Nuclear envelopes and nucleoli form
- Cytoplasm divides to form 2 cells
Trans By: Katherine Mae C. Dela Cruz
Page 7 of 5