H Biology - Unit 2 - KA1 - Metabolic Pathways

What is cell metabolism?

Cell metabolism is the sum of all the anabolic and catabolic reactions taking place in a cell

What is a metabolic pathway?

A metabolic pathway is an integrated series of enzyme controlled reactions

What are anabolic reactions?

Anabolic reactions are reactions inside a cell which build larger more complex molecules from smaller, more simple molecules

Do anabolic reactions release or require energy?

Anabolic reactions require energy

What are catabolic reactions?

Catabolic reactions are reactions inside a cell which break down larger complex molecules into smaller more simple molecules

Do catabolic reactions release or require energy?

Catabolic reactions release energy

What are examples of anabolic reactions within cells?

Examples of anabolic reactions within cells are;

• DNA Replication

• Transcription

• Translation

What is an example of a catabolic reaction within a cell?

An example of a catabolic reaction within a cell is;

• Cellular respiration

What is a metabolite?

A metabolite is a substance used in metabolism

What do metabolic pathways have?

Metabolic pathways have reversible steps, irreversible steps, and alternative routes

What do alternative pathways do?

Alternative pathways produce the same product by taking an alternate route

What is the membrane made up of?

The membrane is made up of;

• Proteins

• Phospholipids

What are phospholipids?

Phospholipids are a type of fat with a hydrophilic head and a hydrophobic tail

How many different roles do proteins in the cell membrane have?

Proteins in the cell membrane have four roles

What are the different roles of proteins in the cell membrane?

The four roles of proteins in the cell membrane are;

• Enzymes

• Receptors

• Pores through the membrane

• Acting as molecular pumps

Why are enzymes involved in metabolism?

Enzymes are involved in metabolism because metabolism is a series of biochemical reactions.

What does splitting do?

Splitting breaks bonds

What does joining do?

Joining makes bonds

What does adding enzymes to a reaction do to the activation energy?

Adding enzymes to a reaction lowers the activation energy needed for the reaction to proceed

When does induced fit occur?

Induced fit occurs after the substrate binds to the active site

What does the active site do during induced fit?

During induced fit, the active site changes shape to better fit the substrate once it has bound

What happens to the products after the reaction has occured?

After a reaction has occurred, the products have a lower affinity for for the active site so they separate

How much affinity does the substrate have for the active site

The substrate has a high affinity for the active site

Where do competitive inhibitors bind?

Competitive inhibitors bind at the active site, preventing the substrate from binding

What can be done to reverse the effect of competitive inhibition?

Increasing substrate concentration can reverse the effect of competitive inhibition

Where do non-competitive inhibitors bind to?

Non-competitive inhibitors bind away from the active site

What do non-competitive inhibitors do?

Non-competitive inhibitors change the shape of the active site, this prevents the substrate from binding.

Can non-competitive inhibition be reversed by increasing substrate concentration?

Non-competitive inhibition cannot be reversed by increasing substrate concentration

When does feedback inhibition occur?

Feedback inhibition occurs when the end product in the metabolic pathway reaches a critical concentration

What does the end product do in feedback inhibition?

In feedback inhibition the end product inhibits an earlier enzyme, this blocks the pathway and prevents further synthesis of the end product

How many types of inhibition are there?

There are three types of inhibition

What are the three types of inhibition?

The three types of inhibition are;

• Competitive inhibition

• Non-competitive inhibition

• Feedback inhibition

What do enzymes control in metabolic pathways?

Enzymes control rate of reaction in metabolic pathways