MCAt cell biology 1

Binary fission

A replication process for prokaryotes, also used by mitochondria

Catalysts

Substances that reduce the activation energy of a chemical reaction.

Centrioles

A set of cylinder shaped structures, that are copied during Interphase, used during Mitosis to anchor Spindle Fibers.

Cellular Respiration

- most efficient catabolic pathway to harvest energy stored in glucose - occurs in mitochondrion and catalyzed by reaction specific enzymes - produces 36-38 ATP - aerobic, O₂ acts as the final acceptor of electrons that are passed from carrier to carrier during the final stage of glucose oxidation - three stages: pyruvate decarboxylation, citric acid cycle and electron transport chain

Autolysis

"Cell suicide" by rupturing of lysosome membranes

Carrier Coenzymes

- NAD⁺, FAD, NADP⁺ - transport the high energy electrons of the hydrogen atoms to a series of carrier moelcules on the inner mitochondrial membrane (electron transport chain)

Cell Division

- a process where a cell doubles its organelles and cytoplasm, replicates its DNA and then divides in two - unicellular organism: reproduction - multicellular organism: growth, development & replace old cells

Binary Fission

- a simple form of asexual reproduction in prokaryotes - circular chromosome replicates - a new plasma membrane and cell wall grow inward along the midline of the cell, dividing it into two - each daughter cell contains a duplicate of the parent chromosome

ADP

- adenosine diphosphate - Pi: inorganic phosphate - ATP --> ADP + Pi + 7 kcal/mole - the 7 kcal/mole provides energy for endergonic/endothermic reactions like muscle contraction, motility and active transport across plasma membranes

AMP

- adenosine monophosphate - PPi: phyrophosphate - ATP --> AMP + PPi + 7 kcal/mole

ATP

- adenosine triphosphate - cell

Allosteric Effects

- allosteric enzyme oscillates between two configuration (active site that can catalyze a reaction and inactive site that can

Active site

- an area on each enzyme to which the substrate bonds to form an enzyme-substrate complex - has a three dimensional shape into which the substrate fits and held at a particular orientation

Apoenzyme

- an enzyme devoid of its necessary cofactor - catalytically inactive

Acrosome

- cap-like structure, over the anterior half of mature spermss head - derived from Golgi apparatus - contains enzymes to penetrate the tough outer covering of the ovum - once in contact with ovum cell membrane, sperm forms a tubelike structure called the acrosomal process - acrosomal process extends and fuses with ovum and enters the ovum

Autoradiography Preparation

- cells are exposed to a radioactive compound for a brief, measured period of time - cells are incubated, fixed at various intervals and processed for microscopy - each preparation is covered with a film of photographic emulsion - preparations must be kept in the dark for several days while radioactive compound decays - the emulsion is then developed - dark silver grains reveal the distribution of radioactivity within the specimen

Carbohydrates

- disaccharides are hydrolyzed into monosaccharides - then converted into glucose or glycolytic intermediates - glycogen in the liver can be converted into glucose 6-phosphate, a glycolytic intermediate

Anaphase I

- disjunction: homologous pairs separate and are pulled to opposite poles of the cell - distribution of homologous chromosomes to intermediate daughter cells are random

Asexual Reproduction

- essentially genetic carbon copies of parent cells - identical to parent cells except for random mutations - different types: binary fission, budding, regeneration, parthenogenesis

Autotrophic

- green plants - convert sunlight into bond energy stored in the bonds of organic compounds (glucose) in the anabolic process of photosythesis - don

Adenine

A nitrogen base that makes up the "rungs" of the DNA ladder;Pairs with Thymine

Capsid

A protein sheath that surrounds the nucleic acid core in a virus

Active Transport

- net movement of dissolved particles against their concentration gradient - need help from transport proteins - requires energy - required to maintain membrane potentials in specialized cells (ex: neurons) - types of molecules transported: polar molecules/ions (Na+, Cl-, K+, etc)

Alcohol Fermentation

- occurs in yeast and bacteria only - pyruvate produced in glycolysis is decarboxylated to acetaldehyde, then reduced by NADH in step 5 of glycolysis to yield ethanol - pyruvate --> acetaldehyde --> ethanol

Binary Fission

- prokaryotesway of of cell division - a type of asexual reproduction - splits into two equal halves, each daughter cell receives a complete copy of the original chromosome

Budding

- replication of the nucleus followed by unequal cytokinesis - the cell membrane pinches inward to form a new cell that is smaller in size but genetically identical to the parent cell - can grow to an adult size - new cell may separate immediately from the parent or remain attached to it - occurs in hydra and yeast

Anaphase II

- sister chromatids are pulled to opposite poles by the spindle fibers

Anaphase

- sister chromatids separate - telomeres are the last part of the chromatids to separate

Centrioles

- specialized type of microtubule involved in spindle organization during cell division - not bound by a membrane - only on animal cells - oriented at right angles to each other and lie in a region called the centrosome - direct separation of chromosomes during cell division - composed of microtubules

Cellular Metabolism

- the sum total of all chemical reactions that take place in a cell - either anabolic (require energy) or catabolic (release energy)

ATP Generation and the Proton Pump

- there are energy losses as electrons are transferred from one complex to the next, this energy is then used to synthesize 1 ATP per complex - since we have 3 complexes, we generate 3 ATP - NADH delivers its electrons to NADH dehydrogenase complex, so for each NADH = 3 ATP - FADH₂ bypasses the NADH dehydrogenase complex and delivers directly to carrier Q (ubiquinone), which is between complex 1 and 2, so each FADH₂ = 2 ATP

Cell Wall

- tough outer cell wall - protects the cell from external stimuli and desiccation - only on plant cells

Centrifugation

- used to separate cells or mixtures of cells without destroying them in process - lower speed: cell mixtures separate into layers on the basis of cell type - high speed: fragmented cells

Autoradiography

- uses radioactive molecules to trace and identify cell structures and biochemical activity - can be used to study protein synthesis - similar techniques are used to study mechanisms of DNA & RNA synthesis

Capsid

- virus

Bacteriophages

- viruses that exclusively infect bacteria - injects its nucleic acid into a bacterial cell, the phage capsid doesnt enter the cell

Alternate Energy Sources

- when glucose supplies run low, the body uses these (in order): carbohydrates, fats and proteins - these are first converted to either glucose or glucose intermediates, which can be degraded in the glycolytic pathway and TCA cycle

Fermentation

/anaerobic process that facilitates the continuation of glycolysis and produces no ATP

Anaphase

Third phase of Mitosis;Centromeres divide which separates the Chromatids, new Chromosomes move to opposite ends of cell, and the cell elongates.

Carrier proteins

Allow larger charged molecules to cross the cell membrane.integral membrane proteins that undergo a conformational change to move a molecule from one side of the membrane to another.

ATP Synthetase

Complex enzyme, in the inner mitochondrial membrane, that permits protons to re-enter the mitochondria and synthesizes ATP using the released energy.

Cell wall

Tough outer layer of a cell made of cellulose, chitin, or other materials

Cell membrane

Encloses the cell; consists of a phospholipid bilayer

cAMP

protein that activate dependent kinases in second messenger cascade that is a universal hunger signal b/c its the second messenger for epi and glucagon

binding of ligand causes GDP to be converted to GTP, which causes the activation of cAMP

Explain G-protein linked receptors.

cell adhesion proteins

proteins that contribute to cell recognition and adhesion.

Autolysis

self-digestion occurring in plant and animal tissues, particularly after they have ceased to function properly

autophagy

self-eating.

centriole

structure that helps to form the spindle

centrioles

structures that are located within the microtubule organizing center and forms microtubules during mitosis to attach to chromosome

alpha amino acid

the amino and carboxyl groups are attached to the same carbon also known as the alpha carbon. Called this because the amine is attached to the carbon in the alpha position.

active transport

the movement of molecules through the plasma membrane against their concentration gradients.

catalase

the primary enzyme in peroxisomes, that catalyzes the hydrolysis of hydrogen peroxide into water and oxygen.

Cell adhesion molecules

Membrane proteins that allow cells to adhere to one another.

cell respiration

the process of using oxygen to release energy from food

cell cycle

the regular sequence of growth and division that cells undergo

Active Site

the specific location where a substrate binds on an enzyme

anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

Active Transport

Movement of particles from a region of particles against a concentration gradient from low to high, utilizing energy.

'Nucleus

Nucleus /- controls activity of the cell, including division - surrounded by a nuclear membrane/envelope that maintains distinct environment from cytoplasm - nuclear membranes have nuclear pores for two way material exchange - contains DNA - histones: structural proteins that form chromosomes - nucleolus: dense structure in the nucleus where ribosomal RNA (rRNA) synthesis occurstrans-stack /portion of golgi furthest from the ER where vesicles are sent out to destination

anaphase

the third phase of mitosis; replicated chromosomes are split apart at their centromeres and moved to opposite sides of the cell.

Centrioles

One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope; play a role in cell division.

catalytic receptors

these have an enzymatic active site on the cytoplasmic side of the membrane that is activated when a ligand binds at the extracellular surface.

Cell

Plasma Membrane /- encloses the cell and composed of phospholipid bilayer - outside: hydrophillic (polar) phosphoric acid - inside: hydrophobic (non-polar) fatty acid - selective permeability: small non-polar molecules pass through/diffuse freely, charged ions, proteins & carbohydrates dont (need carrier proteins to cross) - cholesterol molecules: often embedded in hydrophobic interior & contribute to fluidity - receptors: complex proteins glycoproteins embedded in - membrane with biding sites, may carry molecule into the cell via pinocytosis

Cell Cycle

Process that cells go through over and over in which they increase in size and in number that allows an organism to grow bigger.

apoptosis

Programmed cell death.

Cell adhesion molecules (CAMs)

Proteins that contribute to cell reconition and adhesion

Bound ribosomes

Ribosomes found on the endoplasmic reticulum

Centrioles

Specialized type of microtubule used in cell division in animal cells

cell membrane

thin structure that surrounds a cell

acetyl coa

The entry compound for the Krebs cycle in cellular respiration; formed from a fragment of pyruvate attached to a coenzyme.

Cell Plate

Vesicle like material that develops in the middle of two dividing daughter cells that will become two different cell membranes; one for each daughter cell.

Active Transport

transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient

cancer

uncontrolled cell division

Bacteriophages

viruses that infect bacteria

Actin

The primary component of microfilaments

Bacteriophages

Viruses that can only infect bacteria.

asexual reproduction

a reproductive process that involves only one parent and produces offspring that are identical to the parent

centriole

a structure composed of a ring of nine microtuble triplets, found at the MTOC of a cell; they duplicate during cell division, and sere as the organizing center for the mitotic spindle.

amino acid residue

an amino acid in a polypeptide that is not the N or C terminal AA. This refers to every amino acid in a polypeptide chain.

cell surface receptor

an integral membrane protein that binds extracellular signaling molecules, such as hormones and peptides.

cell

basic unit of structure and function in living things

cell cycle

cell grows, prepares to divide, then divides to start growth process again; interphase + M phase

cell differentiation

cells perform different jobs and specialized tasks

9+2 conformation

cilia/flagella cross section has what conformation?

cancer

disorder in which some of the bodys own cells lose the ability to control growth

cell division

division of a parent cell into daughter cells

acid hydrolases

enzymes that degrade various macromolecules and that require an acidic pH to function properly. found within the lysosomes of cells.

cellulose

hard, nonliving material that makes up the cell wall of a plant cell

bacteria

have cell walls , a cell membrane, cytoplasm, ribosomes, and sometimes flagella. Also respiration occurs at the cell emebrane.

active transport

movement of a molecule that requires energy since it is from low to high concentration

cancer

mutation in protein that regulates progression of cell cycle

cell wall

outer, nonliving part of a plant cell

anaphase

phase of mitosis in which sister chromatids are pulled to opposite sides of the cell

cell division

process by which cells reproduce

3 jobs of the cell membrane

protect, give shape, let materials in and out