matter & energy pathways in living systems

how does photosynthesis work?

chloroplasts of organisms capable of photosynthesis trap solar energy, transforming it into energy-rich materials and oxygen

what is the formula for photosynthesis?

carbon dioxide gas + water + light → glucose (C6H12O6) + oxygen gas

is photosynthesis the most important chemical process on earth?

yes

how do animals obtain carbohydrates?

eating plants or other plant eating animals

how does cellular respiration work?

mitochondria within cells break down high-energy carbs to generate ATP energy (which fuels life functions)

what is the formula for cellular respiration?

glucose + oxygen gas → carbon dioxide + water + 36ATP

what is ATP (adenosine triphosphate)?

direct source of energy for nearly all energy-requiring living organisms

what is ATP used for?

• active transport

• cell division

• directs cilia & flagella

• muscle contraction

• synthesis of various compounds like carbs proteins fats nucleic acids

what kind of chemical reaction does ATP formation perform, and why?

• endothermic reaction (energy trapped)

  • energy must be added/absorbed by the body to create ATP

phosphorylation

addition of a phosphate molecule to regain ATP energy

what is the formula for phosphorylation?

ADP (adenosine diphosphate) + phosphate + energy → ATP (adenosine triphosphate)

dephosphorylation

removal of a phosphorus molecule that releases energy from the bonds of ATP

what is the formula for dephosphorylation?

ATP → ADP + phosphate + energy

chloroplasts

site of photosynthesis, has chlorophyll that performs the process

chlorophyll

pigment that is sensitive to light (photosensitive) that absorbs solar energy + reflects green light

stroma

fluid inside chloroplasts, where light-independent reactions occur

thylakoids

sacs of chlorophyll where light-dependent reactions occur

• contains a photosynthetic membrane

photosynthetic membrane

captures light energy and transforms into ATP energy

grana

stacks of thylakoid disks

carotenoids

accessory pigments that absorb light energy and transfer it to chlorophyll

what kinds of light do carotenoids absorb & reflect?

• reflects yellow light

• absorbs blue + purple light

starch grains

formed due to photosynthesis

draw a diagram of the parts in the chloroplasts.

N/A

what parts are present in the chloroplast?

• chloroplasts

• stroma

• thylakoids

• grana

• carotenoids

• starch grains

why are leaves red and orange during the fall?

• chlorophyll gives plants their green color

  • plants stop producing this in autumn, making the accessory pigments visible to the naked eye.

mitochondria

site of cellular respiration

cristae

inner membrane within mitochondria with many foldings

what are the purpose of the folds in the cristae?

large surface area required for producing ATP (small SA:V ratio!)

matrix

fluid filled region within cristae

what type of muscles use a lot of mitochondria?

liver & muscle cells

draw a diagram of the mitochondria.

metabolic pathways

series of step-by-step reactions where photosynthesis & cellular respiration take place

what type of reaction is cellular respiration

combustion reaction

why are metabolic pathways significant for faciliating photosynthesis & respiration?

• living cells can’t survive the high temperatures and sudden large burst of energy output from a combustion reaction

  • metabolic reactions allow for a slower reaction that won’t kill the cells

how does this sequence of reactions occur?

the product of one reaction becomes a reactant for another

metabolism

all chemical reactions that occur within a cell to sustain its life functions

what are the two types of metabolic reactions?

anabolic & catabolic pathways

anabolic pathways

creates larger molecules from smaller ones

• absorbs energy

catabolic pathways

breaks down larger molecules into smaller ones

• releases energy

enzymes

specialized proteins acting as catalysts reducing the # of energy (lower temps) needed to sustain chemical reactions in the metabolic paths

what would living cells do without enzymes?

• reaction would require a higher temperature to set off

• living organisms would die because of this

oxidation reaction

loss of electrons in a chemical reaction

reduction reaction

gain of electrons in a chemical reaction

when do oxidation and reduction (REDOX) reactions take place?

at the same time

• when one compound gains electrons, the other one loses electrons

when do chemicals contain more chemical energy + reducing power?

in reduced form

create a diagram of how ATP is constantly absorbing and releasing energy.

create a diagram detailing the constant between oxidation & reduction reactions.

the more chemicals you have in a redox reaction:

the more energy that can be transferred through a chain

if you start with a chemical w more energy in a redox reaction:

chain of reactions becomes longer as a constant exchange of electrons occur

what do folds imply in a component?

increased surface area, increased absorption