Module 5 - BIOENERGETICS Flashcards
is the part of biochemistry concerned with the energy involved in making and breaking of chemical bonds in the molecules found in biological organisms.
Bioenergetics
acquire energy from sunlight
photosynthesis
We define life by describing the set of properties that is unique to living things
Nature of Life
is a property that emerges from cellular components, but a collection of those components in the right amounts and proportions is not necessarily alive
Life
6 Properties of living things:
- Make and use the organic molecules of life
- Consist of one or more cells
- Engage in self-sustaining biological processes such as metabolism and homeostasis
- Change over their lifetime, for example by growing, maturing, and aging
- Use DNA as their hereditary material
- Have the collective capacity to adapt to the environment over successive generations
Basic Unit of life
Cell
Cell was first discovered under a microscope by?
antonie van leeuwenhoek
Cell is named by
Robert Hooke
Cell theory was proposed by?
Matthias Jakob Schleiden and Theodor Schwann
What is the cell theory?
- every organism consists of one or more cells
- The cell is the structural and functional unit of all organisms.
- All living cells arise by division of preexisting cells
- Cells contains hereditary material, which they pass to their offspring when they divide
All cells have three common features
- Plasma membrane
- Cytoplasm
- DNA
Separates cell contents from the external environment
Controls exchanges between cell and environment
Plasma membrane
Jellylike mixture of water, sugars, ions, and proteins with all cellular components inside cell
Cytoplasm
The hereditary material of cells
DNA
Most cells are _____ in diameter, much too small to see with the unaided human eye
10-20 micrometers
One _____ is one-thousandth of a millimeter, which is one-thousandth of a meter
micrometer (μm)
Used to visualize cells
Microscope
use visible light to illuminate samples
Light microscope
use electrons to image samples
Electron microscopes
– No nucleus
– Bacteria and archaea
– Single-celled organisms
– Smallest and most metabolically diverse life forms we know
– Share basic structures
Prokaryotes
– Surrounds the plasma membrane
– Made of peptidoglycan (in bacteria) or proteins (in archaea)
– Coated with a sticky capsule
Cell wall
– For motion
Flagellum
– Help cells move across surfaces
– “Sex” pilus aids in sexual reproduction
Pili
– Organelles upon which polypeptides are assembled
Ribosomes
– Irregularly shaped region of cytoplasm containing single large circular DNA molecule
Nucleoid
– Small circles of DNA carrying only a few genes
Plasmids
– DNA contained inside nucleus
– Contain many other membrane-enclosed organelles
Eukaryotic cells
Membranes allow organelles to:
– Regulate substances entering and exiting
– Specialized environment allows organelle to have particular function
Organelles with membranes
- Nucleus
- Endoplasmic reticulum (ER)
- Golgi Body
- Vesicle
- Mitochondrion
- Chloroplast
- Lysosome
- Peroxisome
- Vacuole
Protects, controls access to DNA
Nucleus
Makes, modifies polypeptides and lipids; other tasks
Endoplasmic reticulum (ER)
Modifies and sorts polypeptides and lipids
Golgi body
Transports, stores, or breaks down substances
Vesicle
Makes ATP by glucose breakdown
Mitochondrion
Makes sugar (in plants, some protists)
Chloroplast
Intracellular digestion
lysosome
Breaks down fatty acids, amino acids, toxins.
Peroxisome
Storage, breaks down food or waste
Vacuole
Organelles without membranes
Ribosomes
Centriole
Assemble Polypeptide
Ribosomes
Anchors Cytoskeleton
Centriole
Other component
Cytoskeleton
Contributes to cell shape, internal organization, movement
Cytoskeleton
contains the cell’s DNA, separating it from potential damage in the cytoplasm
Eukaryotic nucleus
DNA and associated proteins in a cell nucleus
Chromatin
Semifluid interior portion of the nucleus
Nucleoplasm
Double membrane with nuclear pores that control which substances enter and exit the nucleus
Nuclear envelope
Dense region of proteins and nucleic acid where ribosomal subunits are being produced
Nucleolus
- Series of interacting organelles between nucleus and plasma membrane
- Makes, modifies, and transports proteins and lipids for secretion or insertion into cell membranes
- Destroys toxins, recycles wastes, and has other specialized functions
The Endomembrane System
An extension of the nuclear envelope that forms a continuous, folded compartment
Endoplasmic reticulum (ER)
Two kinds of endoplasmic reticulum
Rough ER (with ribosomes)
Smooth ER (no ribosomes)
folds polypeptides into their tertiary form
Rough ER
makes lipids, breaks down carbohydrates and lipids, and detoxifies poisons
Smooth ER
Small, membrane-enclosed saclike organelles that store or transport substances
Vesicles
Vesicles containing enzymes that break down hydrogen peroxide, alcohol, and other toxins
Peroxisomes
Vesicles containing enzymes that fuse with vacuoles and digest waste materials
Lysosomes
– Occupies 50 to 90 percent of a cell’s interior
– Stores amino acids, sugars, ions, wastes, toxins
– Fluid pressure keeps plant cells firm
Central vacuole
Many isolate or dispose of waste, debris, and toxins
vacuoles
- A folded membrane containing enzymes that finish polypeptides and lipids delivered by the ER
– Packages finished products in vesicles that carry them to the plasma membrane or to lysosomes
Golgi Bodies
- A folded membrane containing enzymes that finish polypeptides and lipids delivered by the ER
– Packages finished products in vesicles that carry them to the plasma membrane or to lysosomes
Golgi Bodies
- Eukaryotic organelle that makes the energy molecule ATP through aerobic respiration
- Contains two membranes, forming inner and outer compartments
– Buildup of hydrogen ions in the outer compartment drives ATP synthesis
- Has its own DNA and ribosomes
- Resembles bacteria
– May have evolved from aerobic bacteria
Mitochondria
– Organelles that function in photosynthesis or storage in plants and algae
– Includes chromoplasts, amyloplasts, and chloroplasts
Plastids
– Plastids specialized for photosynthesis
– Resemble photosynthetic bacteria
Chloroplasts
- An interconnected system of many protein filaments – some permanent, some temporary
– Parts of the _____ reinforce, organize, and move cell structures, or even a whole cell
cytoskeleton
Cytoskeletal Elements
Microtubules
Microfilaments
Intermediate filaments
– Long, hollow cylinders made of tubulin
– Form dynamic scaffolding for cell processes
Microtubules
– Consist mainly of the globular protein actin
– Make up the cell cortex
Microfilaments
Maintain cell and tissue structures
Intermediate filaments
Accessory proteins that move molecules through cells on tracks of microtubules and microfilaments
Energized by ATP
Example: kinesins
Motor Proteins
what energizes motor protein
ATP
(Adenosine triphosphate)
Example of Motor Proteins
Kinesins
are usually short, hairlike structures that move in waves
Cilia
are long whiplike structures
Flagella
“false feet”
– Temporary, irregular lobes formed by amoebas and some other eukaryotic cells
– Bulge outward to move the cell or engulf prey
– Elongating microfilaments force the lobe to advance in a steady direction
– Motor proteins attached to microfilaments drag the plasma membrane along with
Pseudopods
Many cells secrete materials that form a covering or matrix outside their plasma membrane
Cell surface Specialization
– A nonliving, complex mixture of fibrous proteins and polysaccharides secreted by and surrounding cells
– Structure and function varies with the type of tissue
– Examples: cell walls and cuticles
Extracellular matrix (ECM)
Animal cells do not have _____, but plant cells and many protist and fungal cells do
Cell wall
A thin, pliable wall formed by secretion of cellulose into the coating around young plant cells
Primary cell wall
A strong wall composed of lignin, formed in some plant stems and roots after maturity
Secondary cell wall
A type of ECM secreted by cells at a body surface
Cuticle
consist of waxes and proteins, and help plants retain water and fend off insects
Plant cuticles
Cuticles of crabs, spiders, and other arthropods is mainly _____, a _____
Chitin
polysaccharide
allow cells to interact with each other and the environment
Cell junctions
In plants, _____ extend through cell walls to connect the cytoplasm of two cells
plasmodesmata
Animals have three types of cell junctions:
tight junctions, adhering junctions, gap junctions
Fasten together plasma membranes of adjacent cells
Tight junctions
Fasten cells to one another and to basement membrane
Adhering junctions
Closable channels that connect the cytoplasm of adjoining animal cells
Gap junctions
The _____ by which living cells break down glucose molecules, release energy, and form molecules of ATP.
aerobic process
3 stages of cellular respiration
glycolysis
the citric acid Krebs cycle
oxidative phosphorylation
complete balanced chemical formula for cellular respiration.
C 6 H 12 O 6 + 6 O 2 –> 6 CO 2 + 6 H 2 O + ATP
The first stage of cellular respiration is _____
Glycoloysis
Where does glycolysis takes place?
cytosol of the cytoplasm
The word glycolysis means?
glucose splitting
Enzymes split a molecule of glucose into two molecules of?
pyruvate
_____ is needed at the start of glycolysis to split the glucose molecule into two pyruvate molecules.
Energy
As a result, there is a net gain of _____ molecules during glycolysis.
two ATP
the pyruvate molecules produced at the end of glycolysis are transported into mitochondria, which are sites of cellular respiration. If oxygen is available, aerobic respiration will go forward.
Citric Acid Cycle
During this stage, two turns through the cycle result in all of the carbon atoms from the two pyruvate molecules forming carbon dioxide and the energy from their chemical bonds being stored in a total of 16 energy-carrying molecules (including 4 from glycolysis).
Krebs cycle
takes place on the inner membrane of the mitochondrion. Electrons are transported from molecule to molecule down an electron-transport chain. Some of the energy from the electrons is used to pump hydrogen ions across the membrane, creating an electrochemical gradient that drives the synthesis of many more molecules of ATP.
oxidative phosphorylation
In all three stages of cellular respiration combined, as many as _____ molecules of ATP are produced from just one molecule of glucose.
36
Recall that glycolysis produces two molecules of pyruvate (pyruvic acid). These molecules enter the matrix of a mitochondrion, where they start the
Krebs cycle
Oxidative phosphorylation is the final stage of aerobic cellular respiration. There are two substages of oxidative phosphorylation,
Electron transport chain and Chemiosmosis.
is a series of molecules that transfer electrons from molecule to molecule by chemical reactions.
During this stage, high-energy electrons are released from NADH and FADH2, and they move along ______ on the inner membrane of the mitochondrion.
electron-transport chains
The pumping of hydrogen ions across the inner membrane creates a greater concentration of the ions in the intermembrane space than in the matrix. This gradient causes the ions to flow back across the membrane into the matrix, where their concentration is lower.
Chemiosmosis
