Active Recall - Transport in Animals

What is a tissue?

A group of similar cells working together to perform a common function.

What are organs?

Groups of different tissues that work together to perform a particular function.

What is an enzyme?

Biological catalysts made by proteins that speed up chemical reactions.

What is a catalyst?

A substance that speeds up the rate of a reaction by lowering the activation energy without being used up.

What attaches to the enzyme to catalyze a reaction?

Substrate

What is the active site?

The part of the enzyme with a unique shape that is complementary to the substrate.

Does the substrate fit perfectly to the enzyme?

No, the enzyme slightly changes its shape as it binds to the substrate.

What factors affect enzymes?

Temperature, pH, substrate concentration.

How does temperature affect enzyme activity?

Raising temperature speeds up a reaction, and lowering temperature slows a reaction. But, extreme high temperatures can cause an enzyme to lose its shape (denature) and stop working.

How does pH affect enzyme activity?

Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity.

What is the optimal pH level for enzymes in the stomach?

2, as the stomach is acidic.

How does substrate concentration affect enzyme activity?

A higher concentration increases the rate of a reaction as more substrate will bump into enzymes.

What are the digestive enzymes?

Lipase, amylase, protease, and lactase.

What is the role of the mouth in digestion?

Facilitates physical breakdown by chewing. Saliva makes the mixture liquid (contains amylase).

What is the role of the esophagus in digestion?

Food passes through the esophagus to the stomach.

What is the role of the stomach in digestion?

Contracts muscular wall to push food around and mix it. Produces pepsin (protease enzyme, breaks down proteins) and hydrochloric acid to kill bacteria and provide pepsin with the right environment to work.

What is the role of the pancreas in digestion?

Produces digestive enzymes and pushes it into the small intestine in the form of pancreatic juices.

What is the role of the gall bladder in digestion?

Secretes bile and releases it into the small intestine. Bile is alkaline, so it neutralizes acid from stomach, making pH ideal for digestive enzymes to function. It also breaks big molecules of fat into tiny ones.

How does the small intestine aid in digestion?

The lining of the small intestine has villi, finger-like projections that increase surface area, making diffusion and exchange quicker.

What is the role of the large intestine in digestion?

The large intestine absorbs all of the excess water from watery left over material.

What is the role of the rectum in digestion?

Feces stored here until removed from anus.

What is the role of the lungs?

To get oxygen into the bloodstream where it can be transported to the rest of the body.

What is the process leading up to gas exchange?

Air goes in through nose/mouth, goes down our trachea (wind pipe), divides between two bronchi, further divides between two successive branch like structures (bronchioles), gas exchange happens in alveoli.

Where does gas exchange happen?

Alveoli

Why is the structure of the alveoli effective?

Alveoli have large surface area with millions of alveolis, the walls are moist (allowing for gasses to dissolve, and has the perfect concentration (blood comes from all around the body). All of these allow for increased and faster diffusion.

What does the circulatory system depend on?

Blood, blood vessels, and the heart.

What do veins do?

Carry blood to the heart

What do arteries do?

Carry blood away from the heart.

What do capillaries do?

Exchange nutrients and oxygen with tissues.

What is the lumen?

Cavity within a tubular structure.

Why do arteries have smaller lumen than veins?

To maintain a high blood pressure when carrying blood away from the heart.

How does the structure of a capillary help its role in exchanging substances with cells?

Its walls are single-cell thick, permeable, and blood flows slowly, allowing for more effective and timely exchange of substances.