Cells

organelles

Each cell is a highly organized unit. Within cells, specialised structures called _______ perform specific functions.

Nucleus

is an organelle containing the cells genetic material.

Cytoplasm

• The gel-like substance surrounding the nucleus and filling the cell.

1. Cell metabolism and energy use

2. Synthesize of molecules

3. Communication

4. Reproduction and inheritance

4 Functions of the Cell

Cell Membrane

• also called plasma and is the outermost component of the cell.

• encloses the cytoplasm and forms boundary between the material inside the cell and material outside it.

extracellular substances

substances outside the cell

intracelullar/cytoplasmic substances

substances inside the cells

• supporting the cell contents

• acting as a selective barrier that determines what moves and out of the cell

• playing a role in communication between cells

give other functions of the cell membrane

• (2) major: phospolipids and proteins

• also made up of carbohydrates and cholesterol

Cell membrane is made up of 2 major molecules

Fluid-mosaic model

studies of the arrangement of molecules in the cell membrane have given rise model of its structure.

hydrophilic (water-loving)

hydrophobic (water-fearing)

phospholipids forms double (2) layer of molecules which are called

Selective permeable

Cell membranes are __________, meaning that they allow some substances, but not others, to pass into our out of the cells.

Cholesterol

________ within the phospholipid membrane gives added strength and stability by limiting how phospolipid can move.

proteins

______ function as membrane channels, carrier molecules, receptor molecules, enzymes, or structural supports in the membrane

(1)carbohydrates, (2) glycoprotein

(1) ________ responsible for cell-to-cell recognition and communication. if it attaches to proteins, it is called (2)________

1. inside (intracellular)

2. outside (extraceullar)

Substances such as enzymes, glycogen, and potassium ions (K+) are found in greater concentrations (1) _________ the cell, while Na+Cl²+ and Cl are round in greater concentrations in the (2)________ fluid

Sodium

What is the major extracellular ion?

solvent

these are the substances dissolved

solvent

predominant liquid or gas, where solutes are dissolved.

Diffusion

solute tends to move from an area where it is higher concentration to an area where it is in lower concentration in solution.

Concentration gradient

the solute concentration difference between two point divided bt the distance between the points

Osmosis

the diffusion between of water across a selectively premeable membrane, such as the cell membrane, from a region of higher water concentration to one lower water concentration.

Osmotic pressure

the force required to prevent the movement of water across a selectively permable membrane

Hypotonic solution

a solution has lower concentration of solutes and a higher concentrarion of water relative to the cytoplasm of the cell.

Hypertonic Solution

a solution that has a higher concentration of solutes and a lower concentration of water relatively to the cytoplasm of the cell

Isotonic solution

a solution, where the concentrations of various solutes and water are the same on both sides of the cell membrane

lysis

if the cell swells enough, it can rupture, a process called _______

crenation

when a cell is immersed in a hypertonic solution, resulting in a cell shrinkage or ___________

Facilitated diffusion

a mediated transport process, involving membrane proteins such as channels or carrier proteins, to move substance across the cell membrane.

channels or carrier molecules

other water-suble substances such as ions, diffuse afross the cell membrane by passing through _________ or through ______________

Leak channels

cell membrane channel that constantly allows ions to pass through

Gated channels

cell membrane channel that limits the movement of ions across the membrane by opening and closing

Carrier molecules

are proteins within the cell membrane, also involved in facilitated diffusion

Active transport

• is a process that utilizes membrane proteins to move substances across the cell membrane from regions of lower concentration to those of higher concentration, against a concentration gradient

• Required energy in the form of ATP; if ATP is not available, active transport stops.

Cystic fibrosis

genetic disorder that affects the active transport of Cl- into the cellsm

secondary active transport

uses energy of one substance moving down its concentration gradienr to move another substance across the cell membrane

Cotransport

the diffusing substance moves in the same direction as the transported substance

Countertransport

the diffusing substance moves in a direction opposite to that of the transported substance

Endocytosis

is the movement of materials inside the cells by the formation of a vesicle.

Receptor-mediated endocytosis

involves cell receptors attaching to molecules, which are then transported into the cell.

Phagocytosis

• the cell “eats” large particles such as bacteria, viruses, and dead cells.

• White blood cells and some other cell types eats bacteria, cell debris and foreign particles.

Pinocytosis

• the material is ingested in much smaller and is in solution (to drink)

• cell periodically “drinks” by forming small vesicles around droplets ofextracellular fluid.

• These droplets may have small particles dissolved in them as well.

• These vesicles fuse with lysosomes and release their contents.

Exocytosis

• release of substances fom the cell through fusionof a vesicle with the cell membrane.

• palabas ng cells

secretory vesicle

a membrance bound sac that accumulates materials for release from the cell

Nucleus

• large organelle within the cell

• contains genetic material of the cell.

• mature red blood cells doesn’t have it

nucleolus

• main structure of the nucleus that produces the next organlles which is the ribosomes and containe small units of RNA

• a round structure that is made of the DNA, RNA and proteins.

Nuclear Envelope

consists of an outer membrane and inner membrane that form nuclear pores at many points on the surface of the nucleus

nuclear pores

passageways through which materials can move into or out of the nucleus

chromosomes

this genetic material in the nucleus is organized in 23 pairs of _________ which consists of DNA and proteins.

chromatin

during most of a cell’s life, chromosomes are loosely couled and collectively called ________

Nucleoli

• diffuse bodies with no surrounding membrane that are found within the nucleus.

• usually one to several more within the nucleus.

• consists of rNA and proteins and sre the dites of ribosomal subunit assembly.

Deoxyribonucleic acid (DNA)

is the hereditary material of the cell and controls cell activities.

Ribosomes

• organelles where the proteins are produced (protein synthesis)

• creates proteins for protein synthesis

• composed of one large and one small s

ubunit.

Endoplasmic Reticulum (ER)

series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm

Rough ER

• ER with attached ribosomes

• synthesizing large amount of protein export from the cell

Smooth ER

• ER without attached ribosomes

• responsible for lipid synthesis and participation in detoxificatioj of chemicals within the cells

• in skeletal muscle cells, it stores calcium ions (Ca²+)

Golgi Apparatus

• also called Golgi complex

• consists of closely packed stacks of curved, membrane-bound sacs

• collects, modifies, packages, distributes proteins and lipids manufactured by the Endoplasmic Reticulum (ER)

Secretory vesicles

• a small membrane-bound sac that trasnports or stores materials within cells

• carries substances from Golgi Apparatus and move to the cell membrane. Its membrane then fuses with cell membrane, where its contents are released

Lysosomes

• Membrane-bound vesiclesformed from the Golgi Apparatus

• contains various enzymes that functuon as intracellular digestive system, that breaks down unnecessary by products

• breaks down phagocytized material within the cell

Pompe disease

caused by the inability of lysosomal enzymes to break down the carbohydrate glycogen produced in certain cell.

Peroxisomes

• small membrane-bound vesciles containing enzymes that break roen fatty acids, amino scids, and hydrogen peroxide (H²O²)

Mitochondria

• are small organelles withinner and outer membranes by a space

• major sites of adenosine triphosphate (ATP): ________

• carry out aerobic respiration that requires O²

cristae

major site of adenosine triphosphate (ATP): ________

mitochondrial matrix and mitochondrial DNA (mtDNA)

the material within the inner membrane of the mitochondria _________ and contains enzymes and __________

Cytoskeleton

• internal frame-work of the cell.

• consists of protein structures that support the cell, hold organelles in place, and enable the cell to change shape.

Microtubules

• protein structure of a cytoskeleton that has hollow structures formed from protein subunits

• help support the cytoplasm of cells, assisting in cell division, and forming essential components of certain organelles such as cilia and flagella

Microfilaments

• protein structure of a cytoskeleton that have small fibrils formed from proteins subunits that stucturally support the cytoplasm

• determines cell shape

• some are involve with cell movement

• 
  

Intermediate filaments

• protein structure of a cytoskeleton that has fibrils formed from protein subunits that are smaller in diameter than microfilaments.

• provides mechanical support to the cell.

• types: keratin, protein assosiated with skin cells

Centrisome

• specialized area of cytoplasm close to the nucleus where microtubule formation occurs.

• responsible for cell division

centrioles

• small cylindrical organelle composed of microtubules organized into nine triplets; each triplet consists of 3 parallel microtubules joined together

• centrisomes contains 2 of this small organelle

Cilia

• moves substances/project on the surfaces of the cells

• tiny hair-like structures

• present in the respiratory tract, fallopian tube

flagella

• tail-like/ whip structures, located in the sperm

• similar structure to cilia but much longer

• occur only one per cell: sperm cells

microvilli

• cell membrane extensions of the cell membrane that are supporter by microfilaments, but not move the same as cilia and flagella

• abundant on the surface of cells that line with intestines, kidney, and other areas which absorption is important function

Cell Division

• is the way your body grows and how it replaces worn-out cells and cells damaged by disease or injury

• the formation of daughter cells from a single parent cell

Somatic Cells

• also called as the cells in our body

gametes

Sex cells such as sperm and egg cells are called

Cancer

• when a cell or a group of cells breaks away from the normal control of growth and differentiation

• malignant, spreading tumor

Mitosis

• most cells of the body (somatic cells) divide by this.

• a parent cell divides to form into two daughter cells with the same amount and type of DNA as the parent cell

Prophase

Metaphase

Anaphase

Telophase

4 phases of mitosis: (PMAT)

prophase

• in this phase in mitosis, each chromosome consists of two chromatids joined at the centromere.

• chromatin begin to coil and and condense to form chromosomes

metaphase

at this phase in mitosis, chromosomes line up at the center of the cell

Anaphase

at this phase in mitosis, chromatids separate at the centromere and migrate to opposite poles

Telophase

at this phase in mitosis, the two new nuclei assume their normal structure, and cell division is completed, producing two new daughter cells.

G1 phase

• a growth phase in which proteins are synthesized.

• the cell performs the tasks for which it was created (such as carrying oxygen, secreting digestive enzymes, etc.)

• It accumulates the materials it will need to replicate its DNA

S phase (synthesis)

• when DNA is replicated.

G2 phase

• another growth phase in which proteins are made.

3 stages of Interphase

Meiosis

• Specialized cells called gametes undergo a different process of cell division called _____

• starting cell undergoes two rounds of cell division to produce four haploid cells.