CELS 191 Flashcards
What is the plasma membrane?
Semi-permeable barrier surrounding cell
What are organelles?
Specialized compartments within a cell
What are membrane proteins?
Proteins embedded in the plasma membrane
What is passive transport?
Movement of molecules down concentration gradient
What is active transport?
Movement of molecules against concentration gradient requiring energy
What is co-transport?
Indirect active transport using concentration gradient of one substance
What is diffusion?
Movement of molecules down concentration gradient
What is facilitated diffusion?
Movement of molecules through channels or carriers
What are aquaporins?
Channels allowing water to cross cell membrane
What is cholesterol?
Molecule stabilising membrane fluidity.
What is the Endomembrane System?
Interconnected organelles in eukaryotic cells
The Endomembrane System includes structures such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles.
What is Exocytosis?
Process of material exiting the cell
Exocytosis involves the fusion of vesicles with the plasma membrane to release their contents outside the cell.
What is Endocytosis?
Process of material entering the cell
Endocytosis includes methods such as phagocytosis and pinocytosis, allowing cells to take in substances.
What is a Lysosome?
Organelle with digestive enzymes
Lysosomes break down waste materials and cellular debris, playing a key role in cellular recycling.
What is the Golgi Complex?
Organelle for protein modification and sorting
The Golgi Complex processes proteins received from the endoplasmic reticulum and prepares them for secretion or delivery to other organelles.
What is the cytoskeleton?
Cellular structure providing support, shape, and movement
What is the extracellular matrix?
Non-cellular component of tissues secreted by cells
What are microtubules?
Tubular structures involved in cell motility and shape maintenance
What are microfilaments?
Actin-based structures providing cell movement and shape maintenance
What are intermediate filaments?
Structural proteins maintaining cell shape and anchoring organelles
What are tight junctions?
Cell junctions tightly pressing neighboring cells together
What are desmosomes?
Anchoring junctions connecting sheets of cells
What are gap junctions?
Points of cytoplasmic contact allowing intercellular communication
What is collagen?
Abundant glycoprotein providing tensile strength in ECM
Collagen is a key structural protein in the extracellular matrix (ECM) that contributes to tissue strength and integrity.
What are proteoglycans?
Proteins with sugar additions trapping water in ECM
Proteoglycans play a crucial role in maintaining the hydration and structural integrity of the extracellular matrix.
What are integrins?
Membrane proteins connecting ECM to cytoskeleton
Integrins are essential for cell signaling and adhesion, linking the extracellular matrix to the internal cytoskeleton.
What is a Mitochondrion?
Organelle where most chemical energy is converted into ATP in cellular respiration
Mitochondria are often referred to as the powerhouse of the cell.
What does ATP stand for?
Adenosine Triphosphate
ATP is the main energy carrier of the cell, synthesized in cellular respiration.
What is Oxidative Phosphorylation?
Process in cellular respiration where ATP is produced using high energy electrons
This occurs in the inner mitochondrial membrane.
What is Glycolysis?
Initial stage of cellular respiration, converting glucose into pyruvate
Glycolysis occurs in the cytoplasm and does not require oxygen.
What is the Electron Transport Chain?
Series of protein complexes in inner mitochondrial membrane for ATP production
This chain is essential for aerobic respiration.
What is a Proton Gradient?
Difference in proton concentration across inner mitochondrial membrane
This gradient is crucial for ATP synthesis.
What is a chloroplast?
Organelle where photosynthesis occurs in plant cells
Chloroplasts contain chlorophyll, which captures light energy.
Define photosynthesis.
Process by which plants convert light energy into chemical energy
This process primarily occurs in the leaves of plants.
What does ATP stand for and what is its function?
Adenosine triphosphate, a high-energy molecule used for cellular work
ATP is often referred to as the energy currency of the cell.
What is NADPH?
High-energy electron carrier molecule used in photosynthesis
NADPH is produced during the light reactions of photosynthesis.
What is the Calvin Cycle?
Series of reactions that fix CO2 and produce carbohydrates in photosynthesis
The Calvin Cycle occurs in the stroma of chloroplasts.
What is the function of mitochondria?
Organelle where cellular respiration occurs, producing ATP
Mitochondria are known as the powerhouse of the cell.
What are light reactions?
Initial stage of photosynthesis where light energy is converted to chemical energy
Light reactions take place in the thylakoid membranes of chloroplasts.
What is the stroma?
Fluid-filled space in chloroplasts where the Calvin Cycle occurs
The stroma contains enzymes necessary for synthesizing carbohydrates.
What is a thylakoid?
Membrane-bound compartment in chloroplasts where light reactions take place
Thylakoids are essential for the photosynthesis process, specifically in capturing light energy.
What is the Endosymbiosis Theory?
Theory that explains the origin of chloroplasts and mitochondria
This theory suggests that these organelles were once independent prokaryotic organisms that were engulfed by ancestral eukaryotic cells.
What is a thylakoid?
Membrane-bound compartment in chloroplasts where light reactions take place
Thylakoids are essential for the photosynthesis process, specifically in capturing light energy.
What is the Endosymbiosis Theory?
Theory that explains the origin of chloroplasts and mitochondria
This theory suggests that these organelles were once independent prokaryotic organisms that were engulfed by ancestral eukaryotic cells.
What is the structural layer surrounding plant cells called?
Cell Wall
What is the first layer of the cell wall known as?
Primary Cell Wall
What provides additional strength to the cell wall?
Secondary Cell Wall
What organelle is responsible for storing water and nutrients?
Vacuole
What protein controls cell expansion?
Extensin
What are the channels for cell-to-cell communication called?
Plasmodesmata
What complex polymer provides rigidity to plant cells?
Lignin
What term describes the pressure from water inside plant cells?
Turgor Pressure
Fill in the blank: The movement of water across membranes is called _______.
Osmosis
What is desmotubule?
Structure inside the plasmodesmata.
What is the nucleus
Control center of the cell, contains most genes.
What are Nuclear pores?
Channels controlling molecule movement in/out of the nucleus
What’s is DNA organisation?
DNA packing around histones, forming fibres and chromosomes
What is the Euchromatin?
Less tightly backed DNA with active genes
What is heterochromatin?
Tightly packed DNA with inactive genes.
What are saccharides?
Sugars
What are the different types of saccharides?
Mono-(simple),Di-(made up from two mono),poly-(composed of many sugar monomers)
What are lipids?
They are one class of bio-molecules that does not include true polymers and are not big enough to be considered macromolecules
What are fats made out of?
Made from glycerol and fatty acids
What are fatty acids?
Not polymers. Fatty acid has a long carbon skeleton, usually 16-18 carbons in length one end has a COOH which gives it fatty acids
What are phospholipids?
Is similar to a fat molecule but has two fatty acids attached to the glycerol rather than three
What is a steroid?
Lipids characterised by a carbon skeleton consisting of 4 rings, when you add things to these rings you get new steroids
What is a polypeptide?
Is a set of amino across bonded together by a peptide bond (a polymer of amino acids is called a poly peptide)
What is a protein?
Is a biologically functional molecule made up of one or more polypeptides, each folded and coiled into a specific three dimensional shape.
What is an enzymatic protein?
Selective acceleration of chemical reactions
What do storage proteins do?
Storage of amino acid
What do hormonal proteins do?
Coordination of an organisms activity
What do Contractile and motor proteins do?
Movement
What do defensive proteins do?
Protection against diseases
What do transport proteins do?
Transport of substances
What do receptors proteins do?
Respond of cell chemical stimuli
What do structural proteins do?
Support the structure
What are Nucleic acid?
Is a phosphate, ribose sugar and a base
Most common bases in Nucleic acid?
T (thymine only in DNA), A (adenine), C (cytosine), G (guanine), U (uracil only in RNA)
What is Amylose?
Is a string of monosaccharides
What is starch?
Has two structures, one amylose and one amylopectin is a branch.
What are animal carbs?
Glycogen, like starch but is bigger and has more branches
What do cells have to do? (Cell function)
Make/release stuff, Obtain raw materials, remove waste, generate energy, control all of these
What must the structure of a cell do?
Seperate inside/outside, inside alive, outside non-living, have a boundary (plasma membrane), allows for a specific environment, must be semi-permeable
What does the smooth endoplasmic reticulum do?
Metabolises carbs, lipid synthesis, detoxification, storage of calcium
What does the rough endoplasmic reticulum do?
Involved in protein synthesis, secretes cell or membrane bound proteins enter the lumen
(Is called rough because of the presence of ribosomes)
What is glycosylation?
Adding or modifying carbs or proteins, produces some polysaccharides
What are the types of vesicles?
Membrane bound, fluid filled, transport, secretory, vacuole, liposomes are artificial (vesicles)
What is bulk transport?
The movement of large particles or lots of small molecules.
What is phagocytosis?
The cell eating, the uptake of food particles
What is pinocytosis?
The cell drink, up-take of extra cellular fluid containing various solutes such as proteins and sugars
What does stage one of cellular respiration do?
Glycolysis, in the cytosol it converts glucose into two pyruvate molecules, generates 2ATP and 2 NADH
What is NADH?
High energy electron carrier?
What is are the two parts in the second stage of cellular respiration?
Pyruvate oxidation and Cirtic acid cycle
What is pyruvate Oxidation?
2 pyruvate molecules are converted into 2 Acetyl CoA molecules that enter the citric acid acid cycle, the output is ATP and high energy electron carriers NADH and FADH2
What is the equation of the second stage of cellular respiration?
Glucose+6CO2->6CO2+H2O+ energy
What is the third stage in cellular respiration?
Oxidative Phosphorylation
What are the two parts in oxidative phosphorylation?
The electron transport chain, Chemiosmosis
What happens in the electron transport chain?
NADH and FADH2 shuttle the high energy electrons to the inner mitochondrial membrane, these electrons move through the proteins embedded in the inner membrane, this pumps H+ across the membrane.
What gradient is formed from the electron transport chain?
A H+ gradient, more outside the cell than inside the cell
What happens in Chemiosmosis?
ATP synthase moves protons from the high concentration (outside) to the low concentration (inside) which results in the production of ATP from ADP+P which is powered by the high energy electrons
What are the inputs and outputs of cellular respiration?
Inputs-(glucose, oxygen), outputs-(CO2, water, ATP)
