Cell Bio Exam 2 Flashcards
What is an exergonic reaction?
A reaction that ends with a net release of energy
What is an endergonic reaction?
A rx that requires a net energy input to proceed
What are the three key players in a chemical reaction
Reaction, reactant and product
What is the role of etc?
Consists of enzymes and other molecules that accept or give up electrons one after another, at a cell membrane
In the etc: electrons enter at _____ energy level ➡️ leave cycle with ______ energy level
High
Low
In terms of etc: what is the role of coenzymes in etc?
They deliver electrons to etc in photosynthesis and aerobic respiration
Energy released during the etc cycle does what?
Drives the synthesis of ATP
What are enzymes?
Proteins, one specific substrate, metabolic catalyst
What is a substrate?
The specific reactant acted upon by an enzyme
What is an active site?
Location on enzyme molecule where substrates bind and reaction proceeds
What is the overall reaction for photosynthesis ?
Co2+h20+sunlight ➡️ c6h12o2 + o2 + h2o
What happens in light dependent reactions ?
Light energy is transferred to ATP and nadph.
Water molecules split and release o2
Where do light dependent reactions occur?
In thylakoids
What happens in a light independent reaction?
ATP and nadph (from previous stage) is used to convert co2 to glucose and then to sucrose, starch and cellulose.
Where do light independent reactions occur?
Occur in stroma
What is the role of pigment in photosynthesis?
The pigment captures the light energy necessary for photosynthesis
Who uses the anaerobic metabolic pathway?
Prokaryotes, Protists and muscle cells
Who uses the aerobic metabolic pathway?
Eukaryotic cells
What are the two mitochondrial membranes?
Outer and inner
What is it called to be between two mitochondrial membranes?
Outer compartment
Where does the second stage of aerobic respiration take place?
The inner compartment
What are the two steps that glycolysis is divided into?
ATP requiring steps and ATP generating steps
What does the ATP requiring step of glycolysis involve?
phosphorylation
What does the ATP generating step of glycolysis involve?
1 fructose and 6 bisphosphate is cleaved into 2 pyruvates
What is the net result for glycolysis?
2 net ATP
2 Nadh
2 pyruvates
Describe what happens in the Krebs cycle?
Break down 1 acetyl coA into 2 co2
3 Nadh and 1 fadh2 are formed
2 ATP is formed and regenerates acetyl coA
Where does electron transfer happen?
Inner mitochondrial membrane
What happens in the electron transfer phosphorylation?
Attaches phosphate group to ADP to form ATP
How many net ATP does glycolysis yield?
2 ATP
How many net ATP does Krebs cycle yield?
2 ATP
How many net ATP does the electron transfer yield?
32 ATP
What are the two fermentation pathways?
Alcoholic fermentation and lactate fermentation
What happens in alcoholic fermentation?
Pyruvates is split into acetaldehyde and co2. Acetaldehyde receives electrons and hydrogen from Nadh, forming nad+ and ethanol
What happens in lactate fermentation?
Pyruvate receives electrons and hydrogen from Nadh, forming nad+ and lactate
How are fats used for energy?
Enzymes cleave fats into glycerol and fatty acids when glucose levels fall
What metabolic cycle does glycerol enter once cleaved from fat?
Glycolysis
What metabolic cycle do fatty acids enter once cleaved from fat?
Krebs cycle
How are proteins used for energy?
Enzymes split dietary proteins into amino acids which enter the bloodstream and are used to build proteins or other molecules
What is mitosis?
Growth and replacement of dead or worn out cells, tissue repair
Where does mitosis occur ?
Somatic cells
What is meiosis?
The formation of gametes
Where does meiosis occur?
Germ cells
Describe the g1 phase of interphase:
Uncondensed, no sister
Describe the s phase from interphase:
Uncondensed but duplicated
Describe the g2 phase from interphase:
Condensed and duplicated
Describe prophase
Condense, nuclear membrane breaks down, centrioles move to opposite poles
Describe metaphase:
Chromosomes align between poles, chromosomes condensed
Describe anaphase
Sister chromatids seperate to opposite poles, each chromatid is now a seperate chromosome
Describe telophase
Chromosomes decondense. Nuclear envelope reforms around 2 clusters of chromosomes
Describe cytokinesis in plants
Cell plate formation, cellulose accumulates, thickens, forms a wall
Describe cytokinesis in animals
Cleavage furrow formation ➡️ cytoplasm pinches in two
What are the 5 functions of a cell membrane?
Semipermeable
Helps vesicles form
Separates contents of cell from surroundings
Controls in/out movement through protein channels
Interacts with outside environment
What is a passive transporter?
Allow small molecules through a membrane
What is the function of an active transporter?
goes against a concentration gradient, requires ATP
What is the function of a receptor?
Initiate change in cells activity by responding to an outside signal
What is the function of a cell adhesion molecule?
Helps cell stick to one another
What is the function of recognition proteins?
Identify cells as self
What is the function of an enzyme?
Speed up rx
What is a concentration gradient and from what to what do molecules move to?
Difference in concentration between two adjacent regions. Moves from high ➡️ low
What is diffusion?
A substance diffuses across a lipid bilayer
What is endocytosis
Vesicle movement brings substances in bulk into the cell
What is exocytosis
Vesicle movement ejects substances in bulk from cell
What is osmosis?
High water potential ➡️ low water potential
What does isotonic mean?
Same concentration inside and outside
What does hypertonic mean?
More concentration outside cell
What does hypotonic mean?
More concentration inside cell
