Should I explicitly wait for element to be visible in Protractor test?

If my page is rendered using AJAX request should I execute something like

waitForElementToBeVisible('.todoListItem');
//that is my custom function that waits 
//till element will be rendered

before making call:

element(by.model('todoList.todoText')).sendKeys('write first protractor test');

which sendKeys to element with CSS class .todoListItem?