Photosynthesis & NEURAL SINALLIN SL

Multiple Choice

Most plants appear green because chlorophyll

• absorbs green light.
• absorbs violet light.
• reflects green light.
• does not absorb violet light.

Multiple Choice

What is the pigment in chloroplasts that performs photosynthesis?

• Chlorosynthesis
• Chlorophyll
• ADP
• Electron Transport

Multiple Choice

In which organelle does photosynthesis occur?

• mitochondria

• stomata

• xylem

• chloroplast

Multiple Choice

What gas is being released during photosynthesis

• sulfur
• carbon dioxide
• oxygen
• hydrogen

Multiple Choice

What are the products of photosynthesis?

• Glucose and Chlorophyll
• Glucose and Oxygen
• Water and Light energy
• Carbon Dioxide and Light energy

Multiple Choice

What are the two products of the light reactions that are needed for the calvin cycle?

• NAD and NADPH
• NADP + and Glucose
• NADPH and ATP
• Oxygen and NADPH

Multiple Choice

What is NOT the product of light dependent reaction?

• ATP

• NADPH

• H2O

• O2

Multiple Choice

According to this absorption spectrum, what color is not used by the chlorophyll pigments?

• green
• blue
• yellow
• red

​Interaction & Interdependence
Neural Signalling

Basic ​Parts of the neuron:
1. cell body (soma)
- integrates incoming signals and
generates outgoing signals
2. nerve fibers
a. dendrites
- neuron to neuron
- conduct impulse to the soma
b. axon
- passes signals to other dendrites or effector cells

Other ​Parts of the neuron:
1. axon hillock
- where ACTION POTENTIAL is initiated

2. myelin sheath
- protective layer of fat and protein
produced by Schwann cells
- for efficient transmission of impulse
via SALTATORY CONDUCTION

Other ​Parts of the neuron:

3. node of Ranvier
- gaps in the myelin sheath for SALTATORY CONDUCTION

4. axon terminal
- releases neurotransmitters that relay signals across the synapse

​What would the world be like if you could feel no pain?

Nerve impulses are action potentials propagated along axons of neurons

​Nerve impulse is a result of a change in the concentration of sodium (Na+) and potassium (K+) ions across the membranes of the neuron.

​Na+ is pumped out, K+ is pumped in.
K+ ions leak out.

As a result, the outside of the cell is more positive, the inside of the cell is more negative
( - 70 mV)

​Resting Potential

electrical potential
across the membrane when the cell is at rest
-70 mV

​When a stimulus is received, voltage-gated channels open ( Na channels and then K channels) , an "action potential" occurs.

Action Potential
a. Depolarization
b. Repolarization
c. Hyperpolarization

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Understanding # 2: Myelination of nerve fibers allow for SALTATORY CONDUCTION

Basic ​Parts of the neuron:
1. cell body (soma)
- integrates incoming signals and
generates outgoing signals
2. nerve fibers
a. dendrites
- neuron to neuron
- conduct impulse to the soma
b. axon
- passes signals to other dendrites or effector cells

Impulse Conduction

• Caused by an electrical current 

• Impulse transmission results from the flow of charged particles from one point to another.

• In the body, whenever ions with opposite electrical charges are separated by a membrane, the potential exists for them to move toward one another. This is called membrane potential.

• •A membrane that exhibits membrane potential (an excess of positive ions on one side of the membrane and an excess of negative ions on the other side) is said to be polarized.

Multiple Choice

Impulse transmission results from the flow of

• membrane potential

• charged particles

• negative ions

Impulse Conduction: Step 1 Resting Potential

• When a neuron is not conducting an electrical signal, the interior has a negative electrical charge and the exterior has a positive charge. 

• The outside of the cell is rich with sodium ions (Na+), whereas the inside contains an abundance of potassium ions (K+). 

Impulse Conduction: Step 1 Resting Potential

• The interior also contains other large, negatively-charged proteins and nucleic acids. These additional particles give the cell’s interior its overall negative charge. 

Impulse Conduction: Step 1 Resting Potential

• This state of being inactive and polarized is called resting potential. The neuron is resting, but it has the potential to react if a stimulus comes along. 

Multiple Choice

The state of being inactive and polarized

• Resting potential

• Impulse conduction

Multiple Choice

When a neuron is not conducting an electrical signal, the interior has a negative electrical charge and the exterior has a positive charge.

• True

• False

Impulse Conduction: Step 2 Depolarization

• A stimulus (such as chemicals, heat, or mechanical pressure) causes channels on the neuron’s membrane to open and Na+ from outside the membrane rushes into the cell. 

Impulse Conduction: Step 2 Depolarization

• •The addition of the positively charged ions changes the charge of a region of the cell’s interior from negative to positive. As the membrane becomes more positive, it is said to depolarize.

Multiple Choice

Depolarization is when the membrane becomes more ___________ charged

• Negatively

• positively

Impulse Conduction: Step 3 Action Potential

• If the depolarization goes above the threshold level, adjacent channels also open, which allows more Na+ to enter. This creates an action potential, which means that the neuron has become active as it conducts an impulse along the axon. (Another term for action potential is nerve impulse.)

Step 4 Repolarization

• The sudden influx of Na+ triggers other channels to open; this allows K+ to flow out of the cell.

• Soon after K+ begins to exit, the Na+ channels shut to prevent any more Na+ from flowing into the cell.

• This repolarizes the cell; however, Na+ and K+ are now flip-flopped, with the outside containing more K+ and the inside containing more Na+.

Synapses

• As impulses move from one neuron to the next, they pass through a synapse:

  1.When an action potential reaches a synaptic knob, the membrane depolarizes. Ion channels open and calcium ions enter the cell.

Synapses

• 2.The infusion of calcium causes vesicles to bind to the cell wall and release their store of a neurotransmitter into the synapse.

  3.The neurotransmitter binds to receptors on the postsynaptic membrane. Each neurotransmitter has a specific receptor. (For example, the neurotransmitter epinephrine can only bind to receptors specific to epinephrine.)

Synapses

• 2.The infusion of calcium causes vesicles to bind to the cell wall and release their store of a neurotransmitter into the synapse.

  3.The neurotransmitter binds to receptors on the postsynaptic membrane. Each neurotransmitter has a specific receptor. (For example, the neurotransmitter epinephrine can only bind to receptors specific to epinephrine.)

Synapses

• 5.The receptor releases the neurotransmitter, after which it is reabsorbed by the synaptic knobs and recycled or destroyed by enzymes (as shown here).

Synapses

• 4.The specific neurotransmitter determines whether the impulse continues (called excitation) or whether it is stopped (called inhibition). If the impulse is inhibitory, K+ channels open and the impulse stops. If the neurotransmitter is excitatory—as shown here—Na+ channels open, the membrane becomes depolarized, and the impulse continues.

Synapses

• 5.The receptor releases the neurotransmitter, after which it is reabsorbed by the synaptic knobs and recycled or destroyed by enzymes (as shown here).