Chapter 4 Energy & Cellular Metabolism単語カード | Quizlet

1. all living things are made up of cells

2. all cells come from pre-existing cells

What does Cell Theory say about all living things?

1. have complex structure whose basic unit is the cell

2. acquire, transform, store and use energy

3. sense and respond to internal/external environments

4. maintain homeostasis

5. store, use and transmit info

6. reproduce, develop, grow and die

7. have emergent properties

8. adapt and evolve

What are some things living organisms must be able to do?

autotropic organisms - make their own energy from the environment to produce organic compounds

ex: photosynthesis

How is organic energy produce?

Give an example.

break down organic molecules to release energy

How do autotropic and heterotrophic organisms use organic compounds and stored energy?

energy

the ability to do work

work

use of energy

chemical work

making and breaking bonds

manipulating bonds = manipulating energy

transport work

creation of concentration gradient

cells are constantly moving ions - membrane transport/concentration

mechancial work

movement, energy is used for any type of movement

ex. muscle contraction

kinetic energy

energy of motion

movement - atoms are constantly moving

potential energy

stored energy

chemical bonds that are formed - energy is available but not used yet

1st law of thermodynamics

total amount of energy in the universe is constant - energy cannot be created nor destroyed

just converted to forms useful for work

2nd law of thermodynamics

order to disorder (entropy)

any time you convert energy to something else, some of it is dissipated

When you use muscles for movement, you have to use ATP, this then generates heat as a byproduct

tends toward entropy

convert it to Kinetic energy, this conversion is never 100% efficient

(energy is lost as heat to the environment)

the amount of energy that is lost depends on the efficiency of the process

ex: 70% of the energy used in physical activity is lost as heat rather than transformed into the work of muscle contraction

If you want to use potential energy to do work, what must you do?

reactant (or substrate) -> product

What is the basic chemical equation?

combination

synthesis reaction (building)

Decompisition

degredation reaction (taking apart)

displacements

moving substrates among each other

activation energy

Energy needed to get a reaction started

quick reaction because it doesn't need very much energy to start a reaction

a reaction requiring very low activation energy means

slow reaction because it needs to reach a higher amount of energy before it is able to start the reaction

a reaction requiring very high activation energy means

exergonic reaction

a reaction that gives off energy because the products have less energy than the reactants

endergonic reaction

a reaction that traps some activation energy in the products, which then have more free energy than the reactants.

EX:

ATP -> ADP + Pi (exergonic)

* this decomposition/catabolic reaction gives off energy

* the energy that is given off is then captured

* the captured energy is then used for an endergonic/combination/anabolic reaction (which requires energy)

Explain how endergonic and exergonic reactions work together.

proteins that are biological catalyst - speed up the rate of chemical reaction by lowering the activation energy

they make reaction rates predictable

What are enzymes?

around 7.4

higher or lower than this can decrease enzyme activity

What is the optimal range for enzyme activity in the body?

zymogens

inactive enzymes

-sin

-ase

What are suffixes of enzymes?

they denature depending on temperature and pH

How can enzymes be inactivated?

isozyme

enzymes that catalyze the same reaction but under different conditions or in different tissues

In the hours following a heart attack, damaged heart muscle cells release enzymes into the blood.

Increased levels of isozymes/enzyes like creatine kinase can be measured and used to detect/diagnose whether a heart attacked happened

Why do isozymes play an important role in the diagnosis of certain medical conditions?

Creatine kinase

lactate dehydrogenase

What are some isozymes discussed in class?

metabolism

any metabolic pathway

small steps to get from reactant to final product

catabolism

break down of molecules

can be done by hydrolysis reactions

ex: using water to split molecules

breaking down foods into amino acids, and simple forms

usually gives off energy

anabolism

synthesis of molecules

can be done by synthesis or condensation reactions

ex: building proteins

usually requires energy

in the kilocalrie (kcal) = Calorie (C) = 1000 calories

How is energy measured?

1. by controlling enzyme concentrations

2. by producing modulators that change reaction rates

3. by using two different enzymes to catalyze reversible reactions

4. by compartmentalizing enzymes within intracellular organelles

5. by maintaining an optimum ratio of ATP to ADP

How do cells regulate the flow of molecules through their metabolic pathways?

enzyme modulation

function: alter the activity of a protein

Glucose + water + oxygen -> Carbon dioxide + water + ATP

because energy is given off when we break down glucose to make ATP

What is the overall equation for cellular respiration?

Why is it a catabolic reaction?

1. Glycolysis

2. Oxidation of pyruvate

3. Citric acid cycle (Kreb's)

4. Oxidative phosphorylation

What are the steps of cellular respiration?

glucose -> 2 pyruvate

location: cytosol

made: 2 ATP and 2 NADH

aerobic

What is the goal in glycolysis?

Where does it occur?

What is made during this?

2 pyruvate -> 2 acetyl CoA + CO2

location: mitochondrion

made: 2 NADH

aerobic

What is the goal in oxidation of pyruvate?

Where does it occur?

What is made during this?

acetyl CoA -> 4 CO2

location: mitochondrion

made: 2 ATP, 6 NADH, 2 FADH

aerobic

What is the goal in citric acid cycle (Kreb's)?

Where does it occur?

What is made during this?

To make even more ATP

location: mitochondrion

10 NADH -> 10 NAD + 25 ATP

2 FADH -> FAD + 3 ATP

What is the goal in oxidative phosphorylation?

Where does it occur?

What is made during this?

30-32

How many ATP molecules can one glucose yield?

While glycolysis takes place and does its own cycle

2 pyruvate -> 2 lactate

location: cytosol

uses 2 NADH

ONLY MAKES 2 ATP

When does fermentation occur?

What is its goal?

Where does it occur?

What is made during this?

order of animo acids

- determined by the order of nucleotide bases in DNA

What determines the structure of a polypeptide chain?

20

How many amino acids are there?

4 are start and stop

1 start codon: TAC (DNA) or AUG (RNA)

3 stop codons

Of the 64 codons, how many are start and stop codons?

What is the start codon?

1. transcription

(DNA to mRNA)

2. translation

(mRNA to polypeptide chain)

- transfer RNA (tRNA)

- anticodon

3. Protein sorting

4. Post-translational modification (protein completion)

What is an overview of protein synthesis?

Occurs in nucleus

only activated genes are transcribed

RNA polymerase attaches to the DNA and reads the code spitting out the complement of the strand in the form of mRNA

DNA codon: ACG GAC

mRNA codon: UGC CUG

Where does transcription occur?

What happens?

A-T

C-G

How do bases pair in DNA?

A-U

C-G

How do bases pair in RNA?

mRNA is taken into cytoplasm where ribosomes made of up rRNA attach and begin reading the 3 letter codons

transcriptionRNA (tRNA) carrying a 3 letter anticodon enters the ribosome and if the anticodon matches codon, then that amino acid is bound to the existing chain and the tRNA exits the ribosome making room for the next one

mRNA codons: UGC CUG

tRNA codons: ACG GAC

What happens during translation?

Where does it occur?

protein sorting

specific proteins go from the ribosomes directly to where they are needed in the cell

sorting signal

many newly made proteins carry a sorting signal, an address label that tells the cell where to take the protein

it is a special segment of amino acids (signal sequence)

- directed to appropriate organelle

- packaged in rough ER for storage or export

remains in cytosol

Where do polypeptide chains w/o attached sorting signals go?

fold,

cross-linkage,

splice or cleavage into fragments,

added to other groups,

bind to multiple polypeptide chains

In some common forms of posttranslational modification, the amino acid chain can: