Exam 1 Content Flashcards
How do plants grow?
1.) Production of new cells
2.) Cell enlargement
What do primary meristems do?
-Primary meristems generate new primary tissues at tips of roots and shoots (apical) and at site of new branches (auxiliary bud)
What do secondary meristems do?
-Secondary meristems increase girth of stems and roots
How do plants grow?
New stems and tissues
What are meristems?
Several layers of cells that generate tissues and make up organs
How do plant cells expand?
-increase amount of cytoplasm and number of organelles
-plant cells can take up a lot of water into central vacuole and expand cell walls
-expansion proteins unlock linkages between cell wall components allowing wall to stretch
Plant bodies contain…
cells, tissues, organs, organ systems
Plants grow by…
-production of new cells
-primary apical meristems: apical
-expansion of cells
-new materials
-water uptake
In ionic bonds…
-one atom gives up one or more electrons and becomes positively charged
-other atoms take electrons and become negatively charged
-attraction between oppositely charged ions is called ionic bond
-ex.) Na + Cl forms compound NaCl which can form ions Na+ and Cl-
In covalent bonds…
-form between atoms that share an electron; stronger than ionic bonds
-some atoms may share more than one pair of electrons
-double and triple bonds possible
-carbon has 4 electrons to share
-can share 2 electrons with oxygen atom or another carbon
-can form many different compounds
In hydrogen bonds…
-electrons shared between 2 atoms but atoms differ in size; electrons spend more time traveling around larger atom, so that part of molecule has partial (-) charge
-polar
-water molecules
-partial negative charge on one molecule is attracted to the partial (+) charge on another molecule; called hydrogen bond
-weak bonds
-important in determining characteristics of water
-maintaining correct structure of genetic material
Consequences of hydrogen bonding in water include…
-highly effective solvent- easily dissolve salts, many gases and polar organic compound
-cohesion- water molecules can be drawn from soil up through the roots and tree trunks to leaves to a height of 350 feet
Hydrophilic
-water-loving
-dissolve in water
-charged or polar
Hydrophobic
-water-hating
-don’t dissolve in water (often do in lipids)
-uncharged or non polar
In starch…
Alpha bonds C1 to C4
In cellulose…
Beta bonds C1 to C4
Characteristics of lipids include…
-fats and oils
-energy storage
-made from glycerol and fatty acids (long chains of CH2 groups)
-bends in the chain –> kinks –> don’t pack as tight –> liquid
-saturated fatty acid: all single bonds between C’s
-Monounsaturated: one double bond between C’s
-Polyunsaturated fatty acid: two or more double bonds between C’s
-fats contain mainly saturated fatty acids
-room temp: fats are solid and oils are liquid
-hydrophobic
Characteristics of proteins…
-large molecules made of 20 different amino acids
-most important role “machines” of the cell
-also some storage roles
-amino acids composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
-central carbon group (COOH), an amino group (NH2) and side chain (R)
-side chains (R) determine nature of AA
-hydrophobic, acidic (+), basic (-), polar
-small, large
-kinked
-Proteins tend to fold to expose hydrophilic groups and enclose hydrophobic groups in the interior
How do plants use secondary compounds?
-structural support
-entice animals to aid in reproduction (colors and odors)
-absorb harmful ultraviolet light
-distasteful and poisonous to animals and microbes that attack plants
Main types of plant secondary compounds…
-terpenes and terpenoids
-phenolics and flavinoids
-alkaloids
What is the function of the membrane?
-transport of water by osmosis- diffusion of water across cell membranes
Water moves into or out of cell depending on…
-concentration of dissolved substances (solutes) on both sides of the membrane
-pressure or physical force exerted on water
Osmosis in isotonic solutions looks like…
-same solute concentration as inside cell
-some water will pass through membrane in each direction. Balanced.
Osmosis in hypotonic solutions looks like…
-lower concentration of solutes (higher concentration of water) outside than inside the cell
-water diffuses into cell
Osmosis in hypertonic solutions looks like…
-higher concentration of solutes (lower concentration of water) outside than inside the cell
-water diffuses out of the cell
What is turgor pressure?
pressure within cell from uptake of water
Characteristics of isotonic solutions…
-solute -> same inside and outside
-water -> same inside and outside
-no water movement
Characteristics of hypotonic solutions…
-solute -> low outside, high inside
-water -> high outside, low inside
-water diffuses in
Characteristics of hypertonic solutions…
-solute -> high outside, low inside
-water -> low outside, high inside
-water diffuses out of cell
What is the endomembrane system?
-phospholipid membranes in the cytoplasm
What happened to proteins as they pass through the endomembrane system?
proteins are modified (secondary modifications)
The endoplasmic reticulum is…
-network of flattened membrane sacs and tubes
The rough ER…
-has ribosomes on surface; ribosomes make proteins that will be secreted from cell
The smooth ER…
-makes fatty acids and phospholipids; breaks down toxins
What is the Golgi apparatus?
-stacked array of membrane sacs
What does the Golgi apparatus do?
-each membrane sac within the Golgi apparatus has enzymes for producing and modifying cell materials
-as chemicals are synthesized, part of the Golgi membrane pinches off to form a vesicle carrying the molecules where they’re needed
Characteristics of a chloroplast…
-double membrane
-contain chlorophyll (pigment needed for hypothesis)
-cells may have 40-50
Internal membranes (thylakoids) contain…
chlorophyll and other molecules important for photosynthesis
What contains the other enzymes needed for photosynthesis?
watery stroma
In the mitochondria…
– Folds of inner membrane (cristae) contain enzymes and other molecules important for energy metabolism
– Watery matrix contains other
enzymes for energy metabolism
exergonic means…
reactions release energy
endergonic means…
reactions require energy
What are endergonic and exergonic reactions usually coupled with?
ATP (and other carriers)
– Energy is stored in bond between P groups
How is ATP made?
- Chemiosmosis
– Use Electron Transport Chain to set up a proton
gradient (H+) - ATP synthase protein captures energy as
protons travel “downhill” - Uses energy to add P to ADP
- Occurs in Chloroplasts and Mitochondria
Explain the electron transport chain.
-As electrons move down
chain energy is lowered
-Electron acceptors-
accept and lose
electrons
-Some energy given
off as heat and some
stored in ATP
Photosynthesis is…
6CO2 + 6H2O → C6H12O6 + 6O2
– 1-carbon units (CO2) going to 6-carbon units (glucose)
– Uses water, releases oxygen
– In Chloroplast thylakoids (internal membranes): Electron
Transport Chain, chemiosmosis, and phosphorylation using
ATP synthase
– In Chloroplast stroma: “C link-up reactions” (“fixation” or
“Calvin cycle”)
Respiration is…
6O2 + C6H12O6 → 6H2O + 6CO2
– 6-carbon units (glucose) going to 1-carbon units (CO2)
– Uses oxygen, releases water
In Cytoplasm and Mitochondria matrix: “Glucose Breakdown
Reactions”
– In Mitochondria cristae (internal membranes) Electron
Transport Chain, chemiosmosis, and phosphorylation using
ATP synthase
what does the absorption of light do for photosynthesis?
Plants use visible light for photosynthesis
– right amount of energy to excite electrons in
organic molecules.
– Chlorophyll a absorbs light in the red and blue-
violet region and reflects green light
Chlorophyll a absorption
What does Chlorophyll A do?
- Chlorophyll A: light energy
excites electrons in the ring
structures - electrons jump to a higher
energy level
How is ATP synthesized in the chloroplast?
- Photosystems and electron transport molecules are in
the thylakoid membrane - As electrons pass down the electron transport chain,
part of the energy is used to pump protons (H+) from
stroma of chloroplast into the space inside the
thylakoid membranes - Buildup of positive charges and acidity inside the
thylakoid: an electrochemical gradient - the ATP synthase complex provides a channel for
protons to flow back to the stroma and as they do,
ATP molecules are made by adding phosphate to
ADP.
Explain carbon link-up (“Calvin cycle” or carbon fixation)
- Enzymes and reactions occur in the stroma of chloroplast
- CO2 molecules are hooked together through multiple reactions
- Energy required to hook CO2 molecules together comes from
energy carriers ATP and NADPH
– Breaking the bond releases energy: ATP to ADP and NADPH to NAD - 6 turns of Calvin cycle, each using one CO2 , needed to
produce 1 glucose.
Explain the electron transport chain in mitochondria
- Protein complexes containing electron carrier molecules in
inner mitochondrial membranes - High energy electrons in come from Glucose breakdown
reactions and are carried by NADH and FADH2 - Electrons that have passed through Electron Transport Chain
interact with O2 to from water.
– Poisons which prevent oxygen from accepting electrons (such as
cyanide) shut down the ETC and energy production. - As electrons passed along,
– some energy released used to pump protons across the inner
membrane of the mitochondria to the space between the inner and
outer membranes
– Sets up an electrochemical gradient similar to that in chloroplasts.
