biology bruh jus study

light microscope

100x magnification, visible light passes through the specimen and lenses enlarge the image. can be used to view living cells.

Electron Microscope

1000x magnification, Uses beams of electrons to resolve objects,Has a higher resolution, and able to see cellular organelles

Scanning electron microscopes

(SEMs) examine cell surfaces

Transmission electron microscopes

(TEMs)are useful for

studying the internal structure of a cell.

Cell fractionation

takes cells apart and separates the major organelles from one another

hydrolysis

the chemical breakdown of a compound due to reaction with water.

prokaryotic cells

are older than eukaryotic cells, usually smaller, simpler in structure, have no nucleus, DNA is coiled, cell wall with slime layer, have flagellum

eukaryotic cells

have organelles, have a nucleus that has the DNA, they have cytoplasm

cytoplasm

The region between the nucleus and plasma membrane is the___.  It consists of various organelles suspended in the liquid cytosol

cytosol

the fluid present in the cell and is a constituent of the cytoplasm

Ribosomes

are constructed from a type of RNA, and use the information from the DNA to

make proteins, carry out protein synthesis

plasma membrane

 is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell

phospholipid bilayer

has the phospho lipid which is a head and two fatty acid tails, which is hydrophobic and hydrophilic.helping with liquids in the cell. 

nucleoid

a region of a prokaryotic cell that contains the bacterial chromosome.

organelles

internal membranes that divide the cell into compartments, perform specific functions (divide labor), and isolate reactions from others

endomembrane system

Organelles that are connected and communicate with one another, Directly via membrane channels, and Indirectly via small transport vesicles

chloroplasts

which convert light energy to the chemical energy of food in the process of photosynthesis, found only in plants and algae

Mitochondria

are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP, are found in BOTH plant and animal cells

Nuclear Envelope

The nucleus is separated from the cytoplasm by a double membrane called the____. Pores in the envelope allow materials to move between the nucleus and cytoplasm.

nucleolus

The nucleus contains a dark region in the center called the___,  where ribosomes are made.

Ribosomal RNA

Ribosomes are constructed from a type of RNA called___. They help aid in making of proteins

Chromosomes

In the nucleus, DNA is organized into discrete units called

Chromatin

Each chromosome contains one DNA molecule associated with proteins, called___. It condenses to form discrete chromosomes as a cell prepares to divide. 

vesicle

helps with things such as helping to transport materials that an organism needs to survive

Rough ER

whose surface is studded with ribosomes, Studded with bound ribosomes that synthesize secretory proteins including glycoproteins, Secretory proteins are bound for secretion from the cell, Glycoproteins are proteins covalently bonded to carbohydrates, Distributes secretory proteins in transport vesicles, and Is a membrane factory for the cell

Smooth ER

No bound ribosomes, Site of lipid synthesis,  Enzymes synthesize oils, steroids, and membrane phospholipids, Detoxifies drugs and poisons (especially in liver cells),  Stores calcium ions (in muscle cells), and r eleases of stored calcium ions can trigger muscle contractions

cisternae

packaging, modification, and transport functions for the cell overall

glycoproteins

are proteins covalently bonded to carbohydrates

lysosome

is a membranous sac of hydrolytic enzymes that can digest macromolecules

phagocytosis

The process by which a phagocyte (a type of white blood cell) surrounds and destroys foreign substances (such as bacteria) and removes dead cells

food vacuoles

are formed by phagocytosis, a membrane-enclosed sac, which has a digestive function

Contractile vacuoles

found in many freshwater protists, pump excess water out of cells

peroxisome

are oxidative organelles, are specialized metabolic compartments bounded by a single membrane, found in both plant and animal cells, perform reactions with many different functions, reactions produce hydrogen peroxide and convert it to water using special enzymes

endosymbiont theory

 suggests that an early ancestor of eukaryotes engulfed an oxygen-using non-photosynthetic prokaryotic cell, The engulfed cell formed a relationship with the host cell, becoming an ___.

chlorophyll

Chloroplasts contain the green pigment ___.

cytoskeleton

is a network of fibers that organizes structures and activities in the cell, is dynamic, and contribute to the amoeboid (crawling) movements of,  the protist Amoeba and   some of our white blood cells.

microtubals

  are straight and hollow tubes that maintain cell shape and guide the movement of organelles and chromosomes,  interact with motor proteins to produce cell motility (as in cilia or flagella), and separate chromosomes during cell division

intermediate filaments and micro filaments

are thinner and solid fibers that maintain cell shape, change cell shape, and are involved in muscle contraction.

centrosome

near the nucleus, has a pair of centrioles, each with nine triplets of microtubules arranged in a ring.

centrioles

organizing microtubules that serve as the cell's skeletal system, an organelle that assists cell division, allowing cells to replicate

flagella

A core of microtubules sheathed by the plasma membrane, have an undulating motion like the tail of a fish, allows a cell to move

cilia

microtubule-containing extensions that project from some cells, have a back and forth motion, and A core of microtubules sheathed by the plasma membrane, hair-like structures, also to help move and attach

basal body

that anchors the cilium or flagellum

cell wall

is an extracellular structure that distinguishes plant cells from animal cells, ·      surround the membrane and are made of cellulose,  protect the cells, maintain cell shape, and  keep cells from absorbing too much water.

plasmodesmata

microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between themnels between adjacent plant cells,

Extracellular Matrix

(ECM) Animal cells lack cell walls but are covered by an elaborate___. made up of glycoproteins such as collagen, proteoglycans, and fibronectin, hold cells together in tissues and protects and supports them, proteins bind to receptor proteins in the plasma membrane called integrins, can regulate a cell’s behavior by communicating with a cell through integrins, around a cell can influence the activity of gene in the nucleus, and Mechanical signaling may occur through cytoskeletal changes, that trigger chemical signals in the cell

tight junctions

 membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

Desmosomes

(anchoring junctions) fasten cells together into strong sheets

Gap Junctions

(communicating junctions) provide cytoplasmic channels between adjacent cells

amphipathic

a chemical compound containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure.

fluid mosaic model

a membrane is a fluid structure with a “mosaic” of various proteins embedded in it

Cholesterol

content affects membrane fluidity, lives as a buffer for the bilayer

peripheral proteins

are bound to the surface of the membrane, a protein that is found temporarily attached to the cell or mitochondrial membrane

integral proteins

penetrate the hydrophobic core, a type of membrane protein that is permanently attached to the biological membrane.

transmembrane proteins

Integral proteins that span the membrane are called

glycolipids

 a lipids that has to maintain the stability of the cell membrane and to facilitate cellular recognition

glycoproteins

are formed when the protein component predominates in the combination of carbohydrates and proteins.

selectively permeable

   DEFINITION Allows some substances to move across the membrane. chooses when and when not too. 

Transport proteins

proteins that move molecules across a membrane within a cell, include channel proteins and carrier proteins

aquaporins

facilitate the passage of water through and in a cell

concentration gradient

the region along which the density of a chemical substance increases or decreases

diffusion

the natural movement of particles from an area of higher concentration to an area of lower concentration due to random molecular motion

passive transport

is the diffusion of a substance across a membrane WITHOUT the input of energy.

facilitated diffusion

The passive movement of molecules down their concentration gradient with the help of transport proteins is called

osmosis

The diffusion of water across a selectively permeable membrane is

tonicity

is the ability of a surrounding solution to cause a cell to gain or lose water

isotonic solution

has an equal concentration of solute as that inside a cell

hypertonic solution

has a higher concentration of solute than that inside the cell

hypotonic solution

has a lower concentration of solute than that inside the cell

plasmolysis

 When a plant cell is immersed in a hypertonic solution, the plant cell loses water, shrivels and the plasma membrane pulls away from the cell wall

osmoregulation

is the control of water balance within a cell or organism., 

• The balance of water and solutes outside the cell MUST EQUAL the balance of water and solutes inside the cell, Plant and animal cells maintain

active transport

requires that a cell expend energy to move molecules across a membrane.

uses energy to move solutes against their gradients

membrane potential

is the voltage difference across a membrane, is a source of potential energy for the cell, acts like a battery (an energy source)

electrochemical gradient

Two combined forces, collectively called the _______, drive the diffusion of ions across a membrane

electrogenic pumps

Special transport proteins, called ______, generate the voltage gradient across a membrane. ·      help store energy that can be tapped for cellular work.

proton pump

·      In plants, bacteria, and fungi, a ____ is the major electrogenic pump, actively transporting protons out of the cell and transferring positive charge from the cytoplasm to the extracellular solution.

cotransport

occurs when active transport of a solute indirectly drives transport of other substances. As the solute that has been actively transported across the membrane is allowed to passively diffuse back through a transport protein, its movement can be coupled with the active transport of another substance AGAINST its concentration (or electrochemical) gradient. Plants commonly use the gradient of hydrogen ions generated by proton pumps to drive active transport of nutrients into the cell.

exocytosis

transport vesicles migrate to the membrane, fuse with it, and release their contents outside the cell. Bulk transport across the plasma membrane occurs by___. Many secretory cells use___.

endocytosis

the cell takes in macromolecules by forming vesicles from the plasma membrane. is essentially a reversal of exocytosis.

pinocytosis

(“cellular drinking”), Vesicles form around bulk quantities of liquid or very small particles

receptor mediated endocytosis

a means to import macromolecules from the extracellular fluid, absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane

metabolism

transforms matter and energy, subject to the laws of thermodynamics,  The sum of all the chemical reactions that occur in the body,  Reactants participate in a reaction,  Products form as a result of a reaction

metabolic pathway

Reactions usually occur in a sequence forming a ____, Begins with a particular reactant, Proceeds through several intermediates, Terminates with a particular end product, Each step is catalyzed by a specific enzyme

anabolic pathway

Larger, complex molecules are made from simpler compound, Requires energy

catabolic pathway

Larger, complex molecules are broken down into simpler compounds, Releases energy, Hydrolysis Reactions, Used to decompose/degrade macromolecules into subunits, Water is used to split the substances, Can provide energy for the cell, Metabolic reactions are often reversible

energy

The ability to do work or bring about a change. kinetic, potential, thermal, chemical. cannot be created or destroyed but it can be transferred from one form to another.

kinetic energy

Energy of motion (mechanical energy)

potential energy

Stored energy, Based on matter’s location or structure

thermal energy

is kinetic energy associated with random movement of atoms or molecules, _____in transfer from one object to another is called heat.

chemical energy

is potential energy available for release in a chemical reaction, Energy cannot be created or destroyed but it can be transferred from one form to another.

thermodynamics

is the study of energy transformations

entropy

 is the measure of disorder or randomness, The dispersal of heat/energy in a system.

free energy

The amount of energy available to perform work

exergonic reactions

Products have less free energy than reactants, Spontaneous, releases energy

endergonic reactions

 Products have more free energy than reactants,  Not spontaneous, requires energy

ATP

adenosine triphosphate,

• High energy compound used to drive metabolic reactions, Constantly being generated from adenosine diphosphate (ADP), Composed of Adenine, ribose (together = adenosine), and three phosphate groups

enzymes

Protein molecules that function as catalysts, Speed up reactions, Each enzyme accelerates a specific reaction, Each reaction in a metabolic pathway requires a unique and specific enzyme, The end product will not be formed unless ALL enzymes in the pathway are present and functional

catalyst

a chemical that speeds up chemical reactions.

activation energy

is often supplied in the form of thermal energy that the reactant molecules absorb from their surroundings, The initial energy needed to start a chemical reaction is called the free energy of activation