CELLS Flashcards
Basic unit of life and is composed of a cell membrane and the cytoplasm, which includes organelles such as the nucleus.
Cells
Encloses the cytoplasm and forms a boundary
between the material inside the cell and material outside it.
Plasma membrane
Plasma membrane consists of 2 ___ layers aranged tail to tail
phospholipid (fat)
True or false: the plasma membrane plays a role in communication between cells
True
Contains phosphorus and form a double layer
of molecules in the plasma membrane
Phospholipids
Are phospholipds polar or non-polar?
Polar - water loving
Substances that float among the phospholipid molecules
Proteins
A waxy fat carried through the bloodstream by
lipoproteins and gives added strength and stability by limiting the movement of phospholipids.
Cholesterol
Type of carbohydrate that acts as
surface receptors and stabilize the membrane and are common in brain cells and nerves.
Glycolipids
completely penetrate or extend into the lipid bilayer; controls the entry and removal of specific molecules.
Integral proteins
loosely attached to the exterior surface of the membrane; have various functions.
Peripheral proteins
Largest organelle
Nucleus
The nucleus is bounded by a ___ consisting of a
double membrane which surrounds the nucleus and
separates its fluid content.
Nuclear envelope
formed by the inner and outer membrane of the nucleus where materials can move into or out of the nucleus.
Nuclear pores
forms ribosome subunits.
Nucleoli
Cellular contents between the plasma membrane and the nucleus.
Cytoplasm
Two components of the cytoplasm
cytosol and organelles
Fluid portion of the cytoplasm that surrounds organelles
Cytosol
Consist of protein structure that support the cell, hold organelles in place, and enable the cell to change shape
Cytoskeleton
Components of the cytoskeleton
Microfilaments, intermediate fillaments, microtubules
Small fibrils formed from protein subunits that
structurally support the cytoplasm
Microfilaments
Provide mechanical support to the cell
Intermediate filaments
Assist in cell division and the formation of essential components of certain organelles such as cilia and flagella.
Microtubules
Internal structures that perform functions essential to normal cell structure, maintenance, and metabolism
organelles
Made of microtubules and facilitate chromosome
movement during cell division.
Centrioles
Moves substances over the surface of the cell. Numerous in the respiratory tract
Cilia
Whiplike locomotor organelle much longer than cilia and propel the whole cell
Flagella
Minute finger-shaped projections of the cell
membrane and abundant on the surface that line the intestine, kidneys and other areas in which absorption is an important function
Microvilli
Network of folded membranes connected to the membranous nuclear envelope surrounding the nucleus.
Endoplasmic Reticulum
Studded with ribosomes to synthesize proteins embedded in membranes
Rough ER
No ribosomes attached. Involved in calcium regulation, lipid synthesis, and detoxification.
Smooth ER
Sites of protein synthesis
Ribosomes
scattered throughout the cytoplasm and synthesize proteins used in cytosol
Free ribosomes
attached to the ER and proteins where they are modified and packaged for export
Fixed ribosomes
Functions to collect, modify, package, and distribute proteins and lipids.
Golgi apparatus
Another name for golgi apparatus
Golgi complex
Where is golgi apparatus highly developed?
cells that secrete protein like the salivary glands or the pancreas.
Powerhouse of the cell
Mitochondria
What do you call the inner folds of the mitochondria?
Cristae
Small, membrane bound sacs that transports or stores materials within cells
Vesicles
Membrane-bound vesicles containing intracellular
digestive enzymes
Lysosomes
Where are lysosomes formed?
Golgi apparatus
True or false: Lysosomes remove healthy organelles and pathogens within the cell
False - they remove damaged organelles
Contain enzymes oxidases that can oxidize various organic substances. Can break down fatty acids, amino acids, and hydrogen peroxide
Peroxisomes
Where are peroxisomes abundant?
Cells active in detoxification like the liver and kidneys
Tunnel-like structures, similar to channel protein, and not bounded by membranes. Contain enzymes (proteases) that cut proteins into small peptides
Proteasomes
6 Functions of the cell (GO KAYA MO YAN)
- energy use/metabolism
- synthesis of new molecules
- communication
- reproduction
- protection and support
- movement
Cell membranes are ___ permeable, meaning that they allow some substances, but not others, to pass into or out of the cells.
Selectively
Inside or outside the cell: Enzymes, glycogen, and potassium (K+)
Inside
Inside or outside the cell: Sodium (Na+), calcium (Ca2+), and chloride (Cl-)
Outside
The measure of the amount of a sub-component (especially solute) in a solution
Concentration
difference in concentration between two different areas
Concentration gradient
4 ways molecules can pass through the cell
- diffusion
- membrane channels
- carrier molecules
- vesicles
Type of transport that does NOT require energy, as the substance moves across the concentration gradient. It moves from a high concentration to a low concentration
Passive transport
Movement of solute molecules from an area of higher concentration to an area of lower concentration in a solution
Diffusion
True or false: Diffusion results from the natural, constant random motion of all solutes in a solution
True - REMEMBER! natural and random = diffusion
A form of diffusion that does not require the assistance of membrane proteins
Simple diffusion
What is the energy that fuels simple diffusion?
Kinetic energy
Is a mediated transport process, involving membrane proteins such as channels or carrier proteins, to move substance across the cell membrane.
Facilitated diffusion
completely spans the membrane, and allows certain molecules or ions to diffuse across the membrane.
Transport protein
a type of transport protein, acts like a pore in the membrane that lets water molecules or small ions through quickly
Channel protein
is a transport protein that opens a “gate,” allowing a molecule to pass through the membrane
Gated channel protein
“carry” the ion or molecule across the membrane by changing shape after the binding of the ion or molecule
Carrier protein
True or false: Non-lipid soluble molecules diffuse directly through the cell membrane.
False - Non-lipid soluble molecules diffuse through membrane channels, while lipid-soluble ones diffuse directly through the membrane
Is the diffusion of water across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration.
Osmosis
is the force required to prevent the movement of water across a selectively permeable membrane.
Osmotic Pressure
True or false: The greater the concentration of a solution, the greater is its osmotic pressure and the greater the tendency for water to move into the solution
True
refers to the pressure that any fluid in a confined space exerts
Hydrostatic pressure
concentration of various solutes and water are the same on both sides of the cell membrane
Isotonic solution
Result of isotonic solution
No reaction
has a lower concentration of solutes and higher concentration of water than the cytoplasm of the cell.
Hypotonic
Result of hypotonic solution
Lysis - cells swells enough and ruptures
has a higher concentration of solutes and lower concentration of water than the cytoplasm of the cell.
Hypertonic
Result of hypertonic solution
Crenation - shrinkage of the cell
movement of fluid through partitions containing small holes.
Filtration
In which part of the body does filtration usually occur?
across the wall of small blood vessels - pushing water and dissolved nutrients into the tissues of the body
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
Active transport
Active Transport requires energy in the form of ___
ATP
involves the active transport of one substance, such as Na+, across the cell membrane, establishing a concentration gradient, which then provides the energy for moving a second substance across the membrane.
Secondary active transport
the diffusing substance moves into the same direction as the transported substance.
Contransport
the diffusing substance moves in a direction opposite to that of the transported substance.
Countertransport
this transportation mechanism primarily relies on specialized membrane-bound sacs.
Vesicular transport
involves cells taking in substances from outside the cell by engulfing them in a vesicle derived from the cell membrane.
Endocytosis
ingestion and digestion by cells of substances, such as other cells, bacteria, cell debris, and foreign particles.
Phagocytosis
is distinguished from phagocytosis in that much smaller vesicles are formed and they contain liquid rather than solid particles.
Pinocytosis
is a form of endocytosis in which receptor proteins on the cell surface are used to capture a specific target molecule.
Receptor-mediated endocytosis
is the release of substances from the cell through the fusion of a vesicle with the cell membrane
Exocytosis
process of creating protein molecules.
Protein synthesis
sequence of three nucleotides in mRNA that codes specific amino acids in a
protein.
Condons
During this process, information is stored in a region of the DNA is used to produce complementary RNA molecules called mRNA
Transcription
Is the synthesis of proteins based on the information in mRNA; occurs at ribosomes
Translation
covalent chemical bond between adjacent amino acids in a polypeptide chain
Peptide bond
a trinucleotide sequence located at one end of a transfer RNA (tRNA) molecule, which is complementary to a corresponding codon in a messenger RNA (mRNA) sequence.
Anticodon
is a sequence of amino acids covalently linked by peptide bonds
Polypeptide chain
a series of events that takes place in a cell as it grows and divides
Cell cycle
Longer phase of cell cycle, with high metabolic activity, and where DNA replication happens
Interphase
is the formation of daughter cells from single parent cells
Cell division
- Chromatin condenses into chromosomes
- Centrioles move to the opposite ends
- Spindle fibers extend between the centriole pairs - - Nucleolus and the nuclear envelope disappear
Prophase
- all the genetic material is condensing into chromosomes
- chromatids alignment along the equator of the cell called the equatorial plane.
Metaphase
The centromeres divide, and the sister chromatids of each chromosome are pulled apart.
Anaphase
- nuclear envelopes and the nucleoli form
- mitotic spindle breaks up
- cytoplasm begins to divide to form two cells
Telophase
- Division of the cell’s cytoplasm and organelles
- Formation of cleavage furrow
- Completion of cytokinesis marks the end of cell
division.
Cytokinesis